By William Pearce

In late 1908, John Walter Christie set to work designing and building his last front-wheel drive race car. While the 1909 racer illustrated the continuing evolution of Christie’s front-wheel drive race cars, it also incorporated many features that were a departure from the previous racers (inline racers, 1906 V-4, and 1907 V-4).

J. Walter Christie’s newly completed 1909 front-wheel drive racer in front of the Firestone office at 233 West 58th Street in New York. Note the cylindrical fuel tank at the rear of the vehicle.

Like the previous racers, the 1909 car had its four-cylinder engine mounted transversely between the front drive wheels. The engine’s crankcase housed the transmission and formed the vehicle’s front axle. The cylindrical crankcase was 15.125 in (384 mm) in diameter and made of bronze. Behind the engine was a radiator shaped like an inverted “U” that extended from one side of the vehicle’s frame to the other. Above the vehicle’s rear axle were seats for the driver and passenger (or riding mechanic). The fuel tank was at the extreme rear of the car. The 1909 V-4 racer had a wheelbase around 102 in (2.59 m) and a track around 54 in (1.37 m).

Although the racer was powered by a V-4 like Christie’s previous two racers, the 1909 engine was an entirely new design. Extending from the crankcase toward the rear of the vehicle was a large block to which the individual cylinders were mounted. The sides of this block were integral with the vehicle’s frame. The cylinders of the 1909 V-4 engine were angled so far back that the rear row was just eight degrees from being completely horizontal. The front row of cylinders was angled 20 degrees from the rear row. The cylinders were slanted back to improve the vehicle’s weight distribution and aerodynamics.

The photo on the left illustrates the 1909 Christie racer’s cross shaft (with notched drive gears at its ends) and accessory shaft. The long shaft leading back from the accessory shaft drove the camshaft. The photo on the right shows the overhead camshaft and its drive, the rocker arms, the valves, and the intake manifold. Note the large block between the crankcase and cylinders.

The forged steel crankshaft was 3.5 in (89 mm) in diameter and 19 in (483 mm) long. It had two throws and was supported by two main bearings. Attached to each crankshaft throw was one 30.5 in (775 mm) long (center-to-center) master connecting rod. The master rods served the rear row (lower) cylinders. Attached 7.0 in (178 mm) above each master rod’s big end was a 23.5 in (597 mm) long (center-to-center) articulated connecting rod. The articulated connecting rods served the front row (upper) cylinders. The incredibly long connecting rods allowed the mass of the engine to be placed toward the rear of the car in an effort to further equalize the vehicle’s weight distribution.

The engine’s cylinders had a 7.5 in (191 mm) bore and 7.0 in (178 mm) stroke, which gave the engine total displacement of 1,237 cu in (20.3 L). The engine’s output has been given as various numbers from 100 to 300 hp (75 to 224 kW), but 200 hp (149 kW) is probably close to the correct number. Each cylinder had one intake and one exhaust valve—both were 3.0 in (76 mm) in diameter and mechanically operated. The intake valves were placed on the inner side of the cylinders so that a common intake manifold could feed each row of cylinders. The upper and lower intake manifolds joined at the center of the engine, and the Christie-designed carburetor was bolted to the lower manifold.

Sectional drawing of the 1909 Christie V-4 racer’s crankcase with normal, high-speed drive engaged. The short drive shaft with universal joints on its ends can be seen coupled to the engine’s crankshaft. The front cross shaft is shown with its notched gear straddling the gear of the inner universal joint.

The exhaust valves were on the outer side of the cylinders and positioned so that the exhaust gases for each cylinder vented through a small stack. The valves were actuated by separate rocker arms driven by a single overhead camshaft situated between the two cylinder rows. The camshaft was driven via beveled gears by a long shaft on the left side (from the driver’s perspective) of the engine. The long shaft was driven from the left side of an auxiliary shaft positioned above the engine’s crankcase and in front of the cylinders.

A single spark plug was installed in each cylinder and just under the intake valve. In order to achieve proper timing with the odd cylinder angles, the spark plugs for each row of cylinders were fired by separate magnetos. The magnetos were driven from the extended end of the same long shaft that drove the camshaft.

For normal, high-speed front-wheel drive operation, each end of the crankshaft was coupled via disk clutches to a short drive shaft with universal joints at each end. The short drive shaft was constructed of solid steel and was 2.25 in (57 mm) in diameter. The spindles for the drive wheels were on the outer ends of these shafts. In this configuration, the drive wheels turned once for each revolution of the engine.

The 1909 Christie V-4 racer undergoing final checks before a run. Walter Christie is checking the water level in the radiator’s header tank. Note the thick radiator and the exhaust stacks protruding from the engine cowling.

Machined between the throws at the center of the crankshaft were 1.0 in (25 mm) wide spur teeth that drove the auxiliary shaft positioned above and slightly to the rear of the crankcase. Positioned in front of and driven by the right side of the auxiliary shaft was a cross shaft. This cross shaft could slide to decouple the drive wheels from the crankshaft and engage a reverse gear. In addition, the cross shaft could engage a low-speed gear via an intermediate gear.

Each end of the cross shaft had a notched gear that could mesh with teeth on the inner side of the short drive shaft. For normal, high-speed operation, the notch would align with the teeth on the short drive shaft, allowing for direct drive. For low-speed operation, the cross shaft would slide left, and one side of the notched gear would engage the teeth on the short drive shaft. For reverse, the cross shaft would slide right, mesh with the intermediate gear, and the other side of the notched gear would engage the teeth on the short drive shaft. Shifting levers operated various forks that slid the cross shaft and engaged or disengaged the clutches.

Walter Christie driving the 1909 V-4 racer on Dayton-Ormond Beach in Florida with George Robertson holding on. For the beach runs, special cowlings were installed, the passenger seat was removed, and the radiator’s header tank was altered.

The radiator was formed from 80 copper tubes in 10 sections. Five sections were positioned on each side of the vehicle, and the eight copper tubes of each section formed a half arch. The copper tubes were flattened to a width of 2.625 in (67 mm) and extended from one side of the vehicle’s frame to a header tank positioned at the upper center of the radiator. The complete radiator was 29.25 in (743 mm) high, 35 in (889 mm) wide, and 32.5 in (826 mm) long.

Three different tires sizes were intended to be used on the 1909 racer: 30 in (762 mm) tires for circle tracks, 32 in (813 mm) tires for road use, and 34 in (864 mm) tires for high speed operations. Christie estimated his racer was capable of 130 mph (209 km/h), which equates to an engine speed of 1,285 rpm with the 34 in (864 mm) tires. Christie proposed that an engine with a smaller bore of either 5.5 in (140 mm) or 6.0 in (152 mm) could be used in a touring car version of the racer. These bores would give engine displacements of 665 cu in (10.9 L) and 792 cu in (13.0 L) respectively. However, it is doubtful that engines of these sizes were ever made.

Barney Oldfield in the 1909 Christie racer at one of the many race exhibitions he staged. By this time, the racer had a new radiator and a square fuel tank. The dangerous aspects of the racer were embellished by Oldfield and subsequent owners; the car was even called the “Killer Christie.” It is safe to assume that no car in the 1910s was safe at over 100 mph (160 km/h).

Christie’s new V-4 racer made its public debut on 8 July 1909 at the Blue Bonnets track in Montreal, Canada, but Christie did not find the success he had hoped for. Experiencing some engine trouble, he was able to run a 59.6 second mile (60.4 mph / 97.2 km/h) on the circle track. In the next race, Christie’s car caught fire, taking him out of the event. In early August, the car ran at Grosse Pointe, Michigan where Christie ran a 54.6 second mile (65.9 mph / 106.1 km/h)—a new record for that circle track. Christie’s speed was limited by the track’s insufficient banking, which resulted in him coasting through the turns.

For the remainder of 1909, Christie raced at several tracks but was always plagued by trouble. On the Indianapolis Motor Speedway in mid-December, Christie ran a half mile in 17.53 seconds (102.7 mph / 165.2 km/h). He was slowed again by the turns, completing a mile in 42.58 seconds (84.5 mph / 136.0 km/h). Christie’s former partner (and nephew) Lewis Strang ran a few seconds faster in his 200 hp (149 kW) FIAT.

Oldfield on the Ascot track in Los Angeles, California leading Lincoln Beachey in his Curtiss Pusher in 1913.

George Robertson was hired to drive Christie’s V-4 racer at Ormond-Daytona Beach, Florida in March 1910. The car was fitted with special, aerodynamic front and rear cowlings, and the passenger seat was removed. While the racer did a respectable 32.36 second mile (111.2 mph / 179.0 km/h), it could not approach the 27.33 second mile (131.723 mph / 211.988 km/h) Barney Oldfield had previously run in the 200 hp (149 kW) Blitzen Benz. Robertson went out to make another attempt despite the Christie racer constantly overheating. In the middle of what he felt would be a record-setting run, the engine seized. Once the engine stopped, the drive wheels froze and slid along the sand. This destroyed the tires and damaged the wheels. After much work to repair the vehicle, overheating issues and carburetor problems continued to plague the racer.

Christie had grown tired of all the issues with his racer. He announced that he was done racing and exited the automobile business altogether. The V-4 racer sat until 1912 when Oldfield bought it for $750. A new radiator was installed by either Christie or Oldfield, and the original body was put back on.

Oldfield campaigned the car for four years, putting on show after show. For some of his exhibitions, Oldfield raced against aviation pioneer Lincoln Beachey in his Curtiss Pusher airplane. Oldfield did achieve some success, setting a number of records with the Christie racer. On 20 June 1915, Oldfield set a new American record when he lapped the 2 mile (3.2 km) Speedway Park track in Chicago, Illinois in 64.6 seconds (111.5 mph / 179.4 km/h). On 28 May 1916, Oldfield became the first person to exceed 100 mph (161 km/h) on the 2.5 mile (4.0 km) Indianapolis Motor Speedway track when he completed a lap in 87.7 seconds at 102.623 mph (165.156 km/h). He then upped his 2 mile (3.2 km) American record in Chicago on 5 June 1916 when he completed a lap in 63.75 seconds (112.9 mph / 181.8 km/h).

Oldfield and his crew by the Indianapolis Motor Speedway for their record-setting run in 1916. Leather straps are now used to secure the racer’s cowling, and what appear to be grease cups protrude from the cowl.

Damaged during the run in Chicago, Oldfield sold the car mid-June 1916. The Christie was then used in Ernest Moross’ traveling auto race shows. During World War I, the Christie racer and the rest of the show toured Canada. At some point during this time, the racer was fitted with a new cowl and body. In March 1918, the car was sold to racer Louis Disbrow and continued to be used in various shows. Some of the shows included driver Jerry Wonderlich racing against aviatrix Ruth Law in her Curtiss Pusher aircraft. Outdated and unwieldy, the last of Christie’s front-wheel drive racers was scrapped in Chicago, Illinois around April 1919. All of the bronze parts proved to be the racer’s last payout: $450.

After parting with his racer in 1910, Christie had a short stint in aviation. He then built a series of front-wheel drive fire trucks. These trucks replaced the horses of existing horse-drawn units. This business venture proved quite lucrative. Christie then moved into designing tanks, which occupied his remaining days. Unfortunately, the money faded as the years went by, and Christie died nearly broke on 11 January 1944.

The Christie 1909 racer with its new cowl and body circa 1918. Ruth Law’s Curtiss Pusher is in the background, and her mechanic Bob Westover sits behind the wheel. Note the 300 hp claim and that the racer is still prominently labeled as a “Christie.” (Lee Stohr image via TheOldMotor.com)

Sources:
– “The Front-Wheel-Drives of John Walter Christie, Inventor” by Stan Grayson Automobile Quarterly Volume 14, Number 3 (1976)
– “Christie’s New 100-Horsepower Racer” The Automobile (5 August 1909)
– “Montreal Sees Two-Man Meet” The Motor World (15 July 1909)
– “Christie the Bright Star at Grosse Pointe” The Automobile (5 August 1909)
– “Furious Driving at Fort Erie” The Motor World (12 August 1909)
– “Under the Spell of Speed” The Motor World (26 August 1909)
– “Basle Finishes Miles Ahead” The Motor World (2 September 1909)
– “Oldfield Smashes Florida Beach Records” Automobile Topics (26 March 1910)
– “Rain Cuts Short Florida Record Breaking” Automobile Topics (2 April 1910)
– “Delay Only Increases Race Interest” Motor World (23 June 1915)
– “Oldfield Breaks Record” Motor Age (8 June 1916)
– “Barney’s Christie Junked” Motor Age (24 April 1919)
– Barney Oldfield by William F. Nolan (1961/2002)
– http://www.stohrdesign.com/christie-automobiles-1903-1909-a-blog (various pages)
– http://theoldmotor.com/?p=114991
– http://theoldmotor.com/?p=130800
– http://theoldmotor.com/?p=2798

By William Pearce

Shortly after John Walter Christie wrecked his V-4-powered racer practicing for the 1906 running of the Vanderbilt Cup, he went to work on his next front-wheel drive race car. He took what he learned from his first V-4 racer and from all his inline racers and applied this knowledge while building the new car. Christie planned to take his new racer to Europe as the first American vehicle to compete in the French Grand Prix. At the same time, Christie wanted to expand his Christie Direct Action Motor Car Company and start producing various automobiles of his design.

J. Walter Christie’s 1907 V-4 racer under construction at his shop in New York. The drive shaft for the water pump can be seen behind and to the right of the front wheel and extending toward the bottom of the radiator. This shaft was driven from the bevel gear visible in front of the first row of cylinders.

While the 1907 V-4 racer closely resembled the 1906 V-4 racer, it was an entirely new design. The car’s configuration followed that of the previous Christie racers in which the engine was mounted transversely between the two front wheels. The engine’s crankcase formed the car’s front axle and housed its transmission. The car had two forward gears: a normal gear for high-speed operation and a low gear. There was also a reverse gear. Behind the engine was a large radiator in which individual copper tubes were shaped in an inverted “U” and extended from one side of the frame to the other. A header tank was at the upper center of the tubes. The driver and passenger (typically a riding mechanic) sat over the rear axle with the fuel tank behind them.

The engine’s circular crankcase was made of nickel steel and formed an integral part of the chassis. The individual steel cylinders were mounted in two staggered rows on the crankcase. The first row of cylinders leaned back about 10 degrees from vertical, and the second row was angled about 45 degrees from the first row. Each cylinder was surrounded by a copper water jacket. Cooling water exited the top of each cylinder and flowed through a common manifold to the radiator’s header tank. After flowing through the radiator, the cooled water was pulled through a circulation pump and then flowed into the lower part of the cylinder water jacket. The water pump was driven from the camshaft via a long shaft with beveled gears.

Detail view of the V-4 engine and how its crankcase was an integral part of the car’s frame. The cross shaft on the front of the crankcase drove low and reverse gears. Note the camshaft housing in front of the cylinders and the exhaust valve train. The camel hair lining can just be seen on the outer diameter of the flywheel housed in the crankcase. The clutch would be installed between the flywheel and the crankcase.

Each cylinder had one large, mechanically operated exhaust valve. Via a rocker arm and pushrod, all exhaust valves were actuated by a single camshaft mounted on the outside of the crankcase and in front of the first row of cylinders. From the driver’s position, the right side of the camshaft was geared to the crankshaft, and its left side was geared to the water pump drive shaft. Surrounding the exhaust valve were eight atmospheric (automatic) intake valves mounted in a manganese bronze inlet chamber. The incoming air/fuel charge flowed from the Breeze carburetor, which was positioned behind the engine, into a manifold that branched into separate intake pipes for each cylinder. This configuration gave each cylinder a different induction pipe length and led to unequal air/fuel distribution.

Many sources list the bore and stroke as 7-9/32 in (185 mm) and the total displacement as 1,214 cu in (19.9 L). However, the engine actually had a 7.25 in (184 mm) bore and stroke that gave a total displacement of 1,197 cu in (19.6 L). The 185 mm (7-9/32 in) figure probably originated from the European press rounding up the true 7.25 in (184 mm) number. Regardless, the car’s displacement was the largest of any Grand Prix racer before or since. The V-4 engine reportedly produced around 130 hp (97 kW), but it was probably closer to 100 hp (75 kW).

Christie’s V-4 racer with its full engine cowling. It seems the cowling’s grill was quickly cut away to increase airflow through the radiator. Each cylinder had short exhaust stacks, and the front cylinders expelled their exhaust through the top of the cowl.

The stagger of the cylinders allowed the use of a two-throw crankshaft. Two hollow steel connecting rods were attached to each throw. The crankshaft was supported by three main bearings. The steel pistons had concave heads and five rings; three rings were above the wrist pin, and two bronze rings were below. The underside of the piston had cooling fins to help dissipate heat. For each cylinder, a single spark plug was mounted on its Vee side near the pushrod guide. The spark plugs were fired by a battery-powered Heinz coil and communicator (distributor). The engine used splash lubrication and also a Petersen pressure feed oiler.

On each end of the crankshaft was a manganese bronze flywheel. The outer diameter of the flywheel was lined with woven camel hair to provide a friction surface. Covering the flywheel was a chrome steel cone clutch. Shafts and universal joints connected the drive wheels to the clutches and allowed for steering and independent coil spring suspension. Normal gear would lock the flywheel, clutch, and shaft together so that there was no reduction between the engine and drive wheels; for every revolution of the engine, the drive wheels turned one revolution. Normal engine speed was 1,000 to 1,200 rpm. With its 34 in (864 mm) by 4.5 in (114 mm) front tires, the car was capable of 120 mph (193 km/h) at 1,200 rpm. Of course, different size tires could be used to alter the vehicle’s acceleration and top speed. The rear tires were 34 in (864 mm) by 4 in (102 mm).

Christie and Lewis Strang running in the French Grand Prix in 1907. The car was painted white for the race, the engine cowl had been cut back, exhaust valve covers had been added to the top of the cowl, engine exhaust was now piped out of the cowl and into a muffler (of sorts) seen just behind the front wheel, and crankcase breathers had been added to the front of the car. Note the oil leaking from the camshaft and cross shaft housings.

Low and reverse gears were enabled by a cross shaft on the front of the crankcase. As the cross shaft slid laterally, gears on the shaft meshed with teeth cut into the outside of the clutch drums; at the same time, the clutch disengaged from the flywheel, allowing the speed of the drive wheels to be dictated by the speed of the cross shaft. The cross shaft was geared to the crankshaft at a reduced speed.

The car was only fitted with rear brakes, but two sets were employed. One set of rear brakes acted upon the inner surface of the brake drum while the other set acted upon the drum’s outer surface. The inner and outer brakes were controlled by individual foot pedals; however, the pedals were situated so that both could be pressed simultaneously by one foot.

The rear axle was a hollow steel tube and attached to the frame by semi-elliptic leaf springs. The 25 gal (95 L) fuel tank was easily removed so that it could be inspected by the Grand Prix committee. The car used a pressed steel, channel-section frame. It had a 110 in (2.79 m) wheelbase and a 53 in (1.35 m) track (some sources say a 100 in / 2.54 m wheelbase and a 56 in / 1.42 m track). The car weighed around 1,780 lb (807 kg).

This photo was most likely taken soon after the racer returned from Europe (possibly at Morris Park, New York). The cross shaft, mufflers, and crank case breathers have been removed, but the rest of the car is still in its Grand Prix configuration—apparently still wearing white paint from the Grand Prix. Christie is in the driver’s seat. Note the oil still leaking from the front of the crankcase.

Completed in late April, the Christie racer was tested out on the streets of Long Island, New York at 4 AM. Lewis Strang, who was Christie’s ridding mechanic and nephew, accompanied Christie on this first run. Reportedly, the car broke down after about 20 mi (32 km), but the issues were not severe. The car was repaired and underwent further testing and refinement in May. The racer originally had a cowling that covered the entire engine. Due to cooling issues, the front of this cowling was removed to increase airflow through the radiator. This cowling was continually modified throughout the racer’s life.

In June, Christie, Strang, and the V-4 racer left for France. Thirty-eight cars were entered in the French Grand Prix to be run on 2 July 1907. The race consisted of 10 laps on a 77 km (47.8 mi) course laid out near Dieppe in Northern France. Christie’s racer was the lightest and one of the most powerful racers. It was allocated the race designation WC1 (for Walter Christie 1) and the 12th starting position. The Christie Direct Action Motor Car Company had arranged for several locals to assist with the racer. However, upon arriving in France, Christie and Strang discovered that the helpers were nowhere to be found. Christie and Strang spent their time repainting the car in the white and red colors required for United States racers. They then needed to register the racer in France. With all the administrative work completed, Christie and Strang did not have much time to practice and only made one test lap around the course. This session revealed a sticking exhaust valve, but there was no time for repairs.

Barney Oldfield in the 1907 Christie V-4 racer. It is not known when or where this photo was taken, but a new engine cowling has been installed and the cross shaft has been reinstalled.

Christie and Strang started the race at 6:12 AM and had a tire failure less than two miles later; it was not a good start. Repairs were quickly made, but the car was struggling. Christie picked up the pace and ran a lap in 48 min and 49 sec (58.8 mph / 94.6 km/h). However, this was several minutes slower than the leader. Adding to the trouble of the sticking exhaust valve were a jammed clutch and an overheated main bearing. Christie and Strang retired the V-4 racer on the fifth lap.

Upon return to the United States, Christie was ridiculed for his poor showing at the Grand Prix. He responded that he had spent his own money on his effort, and, unlike other American auto manufactures, he “at least did something.” Christie went on to challenge his critics to a race “for any distance and for any amount of money, and at any time, on any road or track anywhere.” No one stepped up to accept his challenge.

Christie and Strang ran the racer at various tracks to prove its capabilities and those of the Christie Direct Action Motor Car Company. In August, Christie ran a 52.2 second mile (69.0 mph / 111.0 km/h) on the dirt track at Morris Park, New York. He then ran a 52 second lap (69.2 mph / 111.4 km/h) in Boston, Massachusetts followed by the same time at St. Paul, Minnesota. On 9 September, Christie and Strang were running at speed on the Brunots Track near Pittsburg, Pennsylvania when they struck a wrecked racer from a previous crash on the track. Christie lost control of the car, and both men were thrown from their racer. Strang was uninjured, but Christie was hospitalized with a broken wrist, a sprained back, a lacerated head, and abdominal injuries.

Ned Blakely sits behind the wheel of the Christie racer at Ormond Beach, Florida in March 1908. Although Christie made a 109 mph (175 km/h) test run, the car did not finishing any official race.

The V-4 racer was repaired, and Christie and Strang took the car to Birmingham, Alabama. Christie was still recovering from his injuries and did not drive much. The next stop was New Orleans, Louisiana, but the meet was delayed. Christie made arrangements to send the car back to New York and returned there himself. However, the car never arrived. Subsequently, Christie discovered that Strang had taken the car back to Birmingham, Alabama were he set a record on 16 October, lapping the mile track in 51.6 seconds (69.8 mph / 112.3 km/h). Strang also ran the V-4 racer at a few other events.

This unauthorized use of his car deeply upset Christie, and it was the end of his association with Strang. Some of Strang’s behavior can be attributed to the negative influence of his and Christie’s manager, William Pickens. To make matters worse, before Christie knew the car was missing, he had sold it to William Gould Brokaw. The arrangement allowed Christie to continue to drive the 1907 V-4 racer so long as he kept it in good repair. When Christie finally tracked down the missing racer and had it returned to his shop in New York, the engine had a cracked cylinder and other damage.

An undated photo illustrating the many changes made to the 1907 V-4 racer. The cross shaft on the front of the crankcase and the engine cowling have been completely removed. A more conventional radiator has been installed along with new exhaust stacks. A much smaller fuel tank (just in front of the radiator) has replaced the original tank. Note the twin front tires on the right drive wheel. Race promoter Ernest Moross is behind the wheel.

Repairs (which included a new crankcase) were made, and Ned Blakely was tasked with racing the car at Ormond Beach, Florida in March 1908. Unfortunately, in a 100 mi (161 km) race on the first day of the event, a valve broke and took the car out of the race. Repairs were completed, but during a 256 mile (412 km) race on the third day, a spark plug broke off and damaged a cylinder, ending the racer’s participation at the event. Sometime during this event, Christie covered a mile in 33 seconds (109.1 mph / 175.5 km/h) on a test run, but it was not officially timed.

The car was again repaired. In early June, Morton J. Seymour was behind the wheel of the racer practicing for an event on Long Island, New York when he crashed and most likely overturned the car. The radiator was destroyed, but Christie managed to repair the car enough to run without cooling water for an attempt on the 1 km (.62 mi) record. Seymour covered the km in 26.6 seconds (84.1 mph / 135.3 km/h)—not fast enough for a new record.

Another view of the modified 1907 racer. The car still has the twin right drive wheels. Christie is in the driver’s seat. Note how the steering column passes through the radiator.

The racer was repaired yet again and further modified. A new (more conventional) radiator was installed. A small fuel tank was installed in front of the radiator, and the large, rear tank was removed. The low and reverse gears and the engine cowling were completely removed. Seymour and Christie went on to drive the car at a few events. After this, Christie and his good friend Barney Oldfield toured the country and made many appearances at various tracks.

At some point, after the new radiator, the V-4 racer had twin front right wheels installed to help the front-wheel drive vehicle on the circle tracks. It is not clear how often the car ran in this configuration. In December 1908, the racer was running at Tanforan Park near San Francisco, California, but a cracked cylinder took it and its driver Hughie Hughes out of competition. In January 1909, Hughes crashed the car at a race in Phoenix, Arizona, and that was the last known event for Christie’s 1907 V-4 racer; the car’s final disposition is not known. By this time, the Christie Direct Action Motor Car Company had fallen into receivership. Undaunted, Christie had established the Walter Christie Automobile Company in September 1908 and went to work on another V-4 racer.

Note: Some sources state that Blakely ran a 35 second mile in the 1907 V-4 racer at “a beach near Atlantic City” prior to March 1908. However, I was unable to find specifics to this event and feel it may have been confused with the 35.2 second run Christie made at Ventnor Beach, which is near Atlantic City, in 1905.

A photo from the 1908 Minnesota State Fair with Christie, DePalma, and Clark. The fair was held in St. Paul from 31 August to 5 September. Note that the Christie racer has only one front right drive wheel.

Sources:
– “The Front-Wheel-Drives of John Walter Christie, Inventor” by Stan Grayson Automobile Quarterly Volume 14, Number 3 (1976)
– “America’s Candidate for the Grand Prix” by W. F. Bradley The Automobile (11 April 1907)
– “Grand Prix Failures 6. The 1907 Grand Prix Christie” The Bulletin of the Vintage Sports-Car Club No. 281 (Autumn 2013)
– “Christie Racer for the Grand Prix” The Automobile (21 February 1907)
– “The Grand Prix” The Automobile (11 April 1907)
– “Christie Racer is Being Tried Out” The Automobile (2 May 1907)
– “Florida’s Meet Supplied More Records than Races” by John C. Wetmore The Automobile (12 March 1908)
– “Christie’s New 100-Horsepower Racer” The Automobile (5 August 1909)
– http://www.stohrdesign.com/christie-automobiles-1903-1909-a-blog (various pages)
– http://blog.hemmings.com/index.php/2010/05/31/how-strang-met-his-death/
– http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=112329874
– http://hclib.tumblr.com/post/9466387511/auto-racing-at-the-minnesota-state-fair-1908

By William Pearce

In the early 1900s, John Walter Christie built a series of front-wheel drive automobiles; each had its inline, four-cylinder engine mounted transversely between the front wheels. The engine’s crankcase also served as the vehicle’s axle. With only so much room between the wheels, the bore of the engine’s cylinders was limited, and Christie found that other cars were producing more power and outperforming his. In late 1905, Christie devised a way to increase the capacity and power of his engines by using a V-4 configuration.

J. Walter Christie’s 1906 racer after hitting debris on Ormond Beach, Florida in January 1906. Note the exhaust manifolds on the front of the engine, the original cylinder water jackets, and the lack of a radiator header tank. The induction pipe can be seen behind the engine.

After the Vanderbilt Cup race in October 1905, Christie took his 1905 racer, with the 828 cu in (13.6 L), 70 hp (52 kW) inline engine, and modified it with a new V-4 engine. Essentially, the axle of the 1905 racer was reworked to accommodate four individual cylinders. The car maintained its normal (high-speed) gear and low forward and reverse gears. The drive wheels were coupled to the crankshaft, and wheel slip was limited in the normal gear. For low gear and reverse gear, a five to one reduction was employed, and the drive wheels were allowed to slip relative to one another. The individual cylinders were arranged in two rows and were staggered to keep the engine compact. The cylinders were mounted to the top of the axle, and the angle between the rows was around 22.5 degrees.

The carburetor was placed low and behind the engine. The air/fuel mixture traveled from the carburetor and through a large pipe to the top center of the engine. Attached to the end of the pipe was an intake manifold with four outlets to provide the incoming air charge to each cylinder. The air/fuel mixture flowed into each cylinder though a single intake port that led to a chamber ringed around the outer cylinder head. In this ring were eight 1.5 in (38 mm) atmospheric (automatic) intake valves. A single spark plug was positioned below the inlet valve chamber ring.

Christie behind the wheel of his racer at Ventnor Beach, New Jersey in April 1906 . The car had been modified with short exhaust stacks, redesigned cylinder water jackets, and a header tank above the radiator. It was here that Christie set a four-cylinder automobile speed record by covering a mile in 35.2 seconds (102.3 mph / 164.6 km/h).

At the center of the induction ring but separate from it was a single 3.125 in (79 mm) mechanically operated exhaust valve. The exhaust valve was controlled by a rocker arm actuated by a pushrod. The pushrods were driven from a camshaft situated behind the second row of cylinders. Originally, the exhaust valve was enclosed in a housing that had an exhaust port on its side. Each cylinder had its own exhaust manifold attached to the port; this configuration was replaced by a short exhaust stack that extended from the top of the cylinder.

The steel cylinders were originally surrounded by electrolytic (oxygen-free) formed copper water jackets. However, these jackets were prone to leaking and were replaced by jackets made of sheet metal. Water from the radiator entered the water jacket of each cylinder near its bottom. The water flowed out the top of each cylinder and into a common manifold that delivered it back to the radiator/header tank. The radiator was the same originally used with the inline engine in which copper tubes 5/16 in (8 mm) in diameter and 64 in (1.63 m) long were bent into an inverted “U” shape, extending from one side of the vehicle to the other. A header tank was later added above the middle of the radiator. Later still, the header tank was integrated into the middle of the radiator.

Lewis Strang push starting Christie in the 1906 V-4 racer at the Empire City Race Track in May 1906. On this track, Christie tied the then-current mile-track record of Barney Oldfield at 53 seconds (67.9 mph / 109.3 km/h). The racer is shown with an eight section radiator.

Sources disagree on the engine’s size, the engine’s power, and the car’s weight. Some sources list the engine as having a 7.375 in (187 mm) bore and stroke and a total displacement of 1,260 cu in (20.7 L). Other sources give a 7.5 in (191 mm) bore, a 7.0 in (178 mm) stroke, and 1,237 cu in (20.3 L) total displacement. The engine’s output varies by source between 100 to 135 hp (75 to 97 kW), but 100 hp (75 kW) is probably close to the correct figure. The car’s reported weight varies between 1,800 and 2,150 lb (816 to 975 kg). The crankshaft was 2.75 in (70 mm) in diameter and made of chrome steal. It was most likely a two-throw crankshaft supported by three main bearings. This would mean two connecting rods were attached side-by-side to one crankpin. The engine is said to have weighed 470 lb (213 kg).

Christie’s V-4 racer made its debut at Ormond Beach (north of Daytona Beach), Florida in January 1906. The car was numbered 14 for this event and experienced several issues. The right front wheel broke off after the racer struck some debris on the beach during a practice run. The car was repaired, but the copper water jackets leaked, and the car had engine cooling issues. Christie had to stop and refill the radiator with four miles left in the 30 mile race. Christie went on to finish the race in 37 minutes and 24.6 seconds, averaging 48.1 mph (77.4 km/h).

The car’s next appearance was in April at Ventnor Beach, near Atlantic City, New Jersey. The racer was now numbered 4 and was modified with new cylinder water jackets, open exhaust stacks, and the header tank above the radiator. Christie covered a mile in 35.2 seconds at 102.3 mph (164.6 km/h), making the racer the fastest four-cylinder automobile in the world. In May, Christie lapped the mile track at Empire City (Yonkers, New York) in 53 seconds (67.9 mph / 109.3 km/h). This speed tied the mile-track record held by Barney Oldfield.

Christie (at the wheel) and Strang ready for the Vanderbilt Cup race. Note the new header tank and the ten section radiator. Also visible are the springs on the pushrods that held the exhaust valves closed.

By September 1906, Christie had readied his V-4 racer for the Vanderbilt Cup. The car now had the integrated header tank installed, and the radiator had ten sections rather than the eight sections used earlier. George Robertson was to drive the car for the Vanderbilt Cup, but he crashed it during a qualifying run on September 15. The damage was not too severe, and Christie made the repairs that night. However, Christie did not notice that the steering arm had been cracked in the accident.

On the morning of 16 September, Christie and his riding mechanic (and nephew) Lewis Strang took the car out for a test run. As the car quickly gained speed, the steering arm failed and Christie lost control of the racer. The car smashed into a telegraph pole and was too damaged to be repaired. Fortunately, Christie and Strang were not injured. The pair went on to race in the 1906 Vanderbilt Cup in a converted touring car that the Christie Direct Action Motor Car Company had built. After the race, Christie went to work on his next racer; he had already set his sights on putting his front-wheel drive cars on the international stage.

The destroyed Christie 1906 V-4 racer after the steering arm broke on 16 September. Note how the steering wheel was broken in the accident. Fortunately, Christie and Strang were not injured.

Sources:
– “The Front-Wheel-Drives of John Walter Christie, Inventor” by Stan Grayson Automobile Quarterly Volume 14, Number 3 (1976)
– “The Reconstructed Christie racer and Its Record at the Automobile Carnival” Scientific American (9 June 1906)
– “Record-Holding Racers at the Ormond Automobile Meet” Scientific American (10 February 1906)
– “Now for the Selection of the American Cup Team” The Motor Way (20 September 1906)
– “Christie’s New 100-Horsepower Racer” The Automobile (5 August 1909)
– http://www.stohrdesign.com/christie-automobiles-1903-1909-a-blog (various pages)
– http://www.vanderbiltcupraces.com (various pages)

By William Pearce

John Walter Christie was born in New Milford, New Jersey on 6 May 1865. From 1881 to 1900 (age 16 to 25), he worked in and was a consultant for various engineering firms. During this time, he designed a new style of gun turret for Navy ships. This design proved lucrative, and in 1900, Christie opened his own machine shop, Walter Christie Machinery, in New York City, New York. He opened the Christie Iron Works the very next year in 1901. As the dawn of the automotive age shone on the United States, the successful Christie was able to own an automobile, but the engineer in him could not help but see ways to improve its design.

J. Walter Christie in his 1903 front-wheel drive auto, the first built in the United States. Just visible behind the rear wheel is the radiator. Christie took this car to Ormond Beach, Florida in January 1904.

By late 1903, Christie had built his own automobile, and it was unlike any other. He designed not only the car but also its engine and transmission. Christie felt that an automobile drive system should pull the vehicle (like a train or carriage), not push it (like a boat). As a result, Christie focused on a front-wheel drive system in which the engine was situated transversely between the front wheels. He believed this arrangement would create a light, simple, high-speed auto. Christie’s first vehicle design closely followed a patent that he took out in 1904. Christie’s front-wheel drive car was the first of its kind built in the United States.

The front axle of Christie’s auto was also the engine’s crankcase and housed its transmission. The cylinder block was mounted atop the axle housing. The auto had a low gear and a reverse gear; both provided a five to one reduction and enabled the drive wheels to slip relative to one another. For normal (high-speed) operation, the drive wheels were coupled to the crankshaft and wheel slip was limited. Each drive wheel had a clutch to facilitate the gear change. In addition, each drive wheel had two universal joints, and shafts that allowed for steering and independent coil spring suspension. The rear axle used leaf spring suspension.

A drawing from Christie’s 1904 patent illustrating the front-wheel drive system’s drive shafts, universal joints, and coil spring suspension. Note the offset X-beams of the connecting rods.

The 1903 car originally accommodated a driver and passenger (or mechanic, which for Christie was often his nephew Lewis Strang), but it was later fitted with a second row of seats for three passengers. The car only had rear brakes, and they were operated by a hand lever or a foot pedal. The auto weighted about 1,400 lb (635 kg). The engine for the 1903 car is believed to have had a 5.0 in (127 mm) bore and a 6.0 in (152 mm) stroke. It displaced 471 cu in (7.7 L) and produced around 30 hp (22 kW). The connecting rods were of the X-beam type. The X-beam was offset relative to the crankpin to allow for a shorter crankshaft and to provide clearance for the crankshaft’s three main bearings. A handle for crank-starting the engine protruded from the front of the axle, but the car was typically push started.

The engine had an intake over exhaust (F-head) valve arrangement. A set of four intake valves with a small combustion chamber space beneath them was positioned adjacent to the cylinder. The intake valves were atmospheric (or automatic): they were held closed by a weak spring and pulled open by the vacuum created during the piston’s downward stroke. A single, large exhaust valve was situated under the intake valves. The exhaust valves were mechanically operated. They were actuated by pushrods driven by a camshaft geared to the engine’s crankshaft. Each cylinder had a single spark plug positioned in the combustion chamber space between the exhaust valve and intake valves. The spark plugs were fired by a communicator (distributor) driven from an auxiliary shaft.

The 606 cu in (9.9 L), 30 hp (22 kW) engine of the 1903 Christie car. The spark plugs are in the center of the combustion chamber space adjacent to the cylinders. A set of four intake valves are above each spark plug, with a single exhaust valve below. Note the exhaust manifold. The hand crank on the front of the car was used to start the engine.

For induction, the air/fuel mixture flowed from a remote carburetor and through a long intake pipe to the engine. The intake manifold sat atop the engine and was split into four runners. Each runner connected to one group of four intake valves

The engine’s cylinders were covered by water jackets formed from sheet copper and screwed to the cylinder block. A remote water pump drew cooling water from the radiator and sent it to the engine. After flowing through the engine, the cooling water was taken from the top of the engine and sent to the radiator. The radiator was positioned under the rear of the car for better weight distribution. The water pump was driven from the same shaft that drove the ignition system’s communicator.

Christie’s 1904 racer with its unusual radiator and eight-intake-valves-per-cylinder engine. Christie sits in the driver’s seat.

Christie took the 1903 car to Ormond Beach, Florida (just north of Daytona Beach) in January 1904. In his car, Christie averaged 63.1 mph (101.5 km/h) in a 10 mile (16 km) race and completed a 25 mile (40 km) endurance race. However, the engine did experience some issues from lack of lubrication. Christie continued to campaign this car at a few events, but he also built a larger car more dedicated to racing in 1904.

Christie’s 1904 racer used an engine of similar configuration to the 1903 engine. However, each cylinder had two sets of intake valves, for a total of eight per cylinder. The new set of four intake valves was positioned directly above the piston. Each of the four intake runners that sat atop the engine had two outlets, one for each set of four valves. The engine’s bore and stroke were 6.25 in (159 mm) and 6.75 in (171 mm) respectively. The engine had a total displacement of 828 cu in (13.6 L) and produced 70 hp (52 kW). Its crankshaft and pistons were made of carbon steel, and its crankcase and flywheels were made of a manganese bronze alloy. The spark plugs were fired from a battery powered coil ignition.

A close up of the engine in the 1904 Christie racer. Note the springs for the mechanical exhaust valves, the lack of an exhaust manifold, and the outlet for the sheet copper water jacket.

In the 1904 car, the driver and passenger were moved to the extreme rear of the vehicle for better weight distribution. In addition, the fuel tank was situated under the seat. A new radiator was installed in the middle of the auto. It consisted of around 60 long, copper tubes shaped in an inverted “U” extending from one side of the car to the other. The radiator was positioned so that air passed over it rather than through it; this configuration limited its effectiveness. No information regarding where or if the 1904 car was raced has been found. Some believe that it was a modification of the 1903 car, but it was not; the engine, axle, and frame were all different.

Christie continued to develop his concept of the front-wheel drive racer and built another car toward the end of 1904. The car, sometimes referred to as the Blue Flyer, made its debut at Ormond Beach in January 1905. It was very similar to the 1904 racer but had a new frame and axle. The car was powered by the same 70 hp, 36-valve (four being exhaust), four-cylinder engine used in the 1904 car. However, its orientation had been changed so that the exhaust valves were toward the rear of the vehicle.

The engine of the 1905 Christie racer was the same used in the 1904 racer; it was repositioned so that the exhaust valves faced toward the rear of the vehicle. The protuberance on the front of the engine was the water jacket outlet used on the 1904 car. The two sets of four valves for one cylinder are visible in the right image.

A new radiator was developed consisting of 12 sections (although photos seem to indicate only eight sections). Each of the sections was made up of eight copper tubes that were 5/16 in (8 mm) in diameter and 64 in (1.63 m) long. Attached to each section were 340 aluminum fins that were 5 in (127 mm) long and 1 in (25 mm) wide. Reportedly, this gave the radiator a surface area of some 20,000 sq in (12.9 sq m), but as with the earlier radiator, air flowed over its surface. Cooling water was taken from the water jacket between the cylinders and delivered to an expansion tank in front of the radiator. The water then flowed through the radiator and into the bottom of the water jacket on both sides of the engine. The 1905 racer had a 96 in (2.44 m) wheel base, a 57.5 in (1.46 m) track, and weighed 1,800 lb (816 kg).

For each revolution of its 40 in (1 m) wheels, the car travel 10 feet (3 m) forward. Given the car’s direct drive, 90 mph (145 km/h) would be achieved at 792 rpm. Christie raced the car on Ormond Beach in January 1905 and covered a mile in 42.2 seconds (85.3 mph / 137.3 km/h). Christie went on to win a 50 mile (80 km) race and received the Lozier Trophy. However, his was the only car to finish the race. Regardless, people were impressed by Christie and his automobiles. Based on the interest in his vehicles, Christie formed the Christie Direct Action Motor Car Company in March 1905 to manufacture passenger and race cars.

This image shows Christie’s 1905 racer modified with a second engine. The rear engine appears to be identical to the engine used in the 1903 car. The radiator appears to have eight sections.

In search of more power, Christie installed a second engine in the 1905 car. The car was lengthened, and the second engine was installed behind the driver and passenger. The second engine produced around 30 hp and powered the rear wheels. The engine appears to be the same four intake and one exhaust valve engine used in the 1903 car (and used in the 1906 car described below). The two engines provided a total of around 100 hp (75 kW). The twin-engined car made its debut on 4 July at Morris Park, New York. The car proved to be a handful but went on to run at Cape May, New Jersey in July, where it covered a mile in 37.0 seconds (97.3 mph / 156.6 km/h). In August, Christie ran a km in 25 seconds (89.5 mph / 144.0 km/h). In September, that flying km time was lowered to 23.25 seconds (96.2 mph / 154.8 km/h), for which Christie won the Cape May Trophy. Later in September, the rear engine was removed from the racer after it failed while Christie was attempting a new mile record. (It appears two additional radiator sections were added at this time, bringing the total to 10.)

Christie then set his sights on the Vanderbilt Cup race scheduled for 14 October in Long Island, New York. George Robertson was selected to drive the car in the race, but he was not familiar with the peculiarities of the car and its front-wheel drive. Robertson had trouble during qualifications on 23 September and ultimately crashed the car. The needed repairs took too long, and Christie’s car was out. However, the Cup Commission made a bizarre decision that is still not understood. Three qualified cars were removed from the race, and three cars that did not qualify were reinstated; Christie’s racer was one of the three reinstated cars.

Christie and George Robertson sit in the 1905 racer ready for a Vanderbilt Cup practice run . The rear engine has been removed, and the radiator now has 10 sections. Robertson crashed the car a short time later.

Christie worked feverishly, almost up to the start of the race, to completely repair his racer, which had suffered some engine damage. Christie drove his car in the race due to Robertson’s inexperience with the unique racer. At the start, Christie’s 1905 racer ran poorly and completed the first lap at only 29.2 mph (47.0 km/h). The engine then smoothed out, and the second lap passed at 56.0 mph (90.1 km/h). On the fourth lap, Italian driver, and race leader, Vincenso Lancia left the pits right as Christie was speeding by. Christie tried unsuccessfully to avoid a collision. Both drivers and their mechanics escaped with only minor injuries. Christie’s car was damaged beyond repair, and the time needed to repair Lancia’s car effectively took him out of contention.

Christie rebuilt the 1905 racer with a new V-4 engine. The car made its debut in January 1906. Unfortunately, it crashed on 16 September during qualification for the 1906 running of the Vanderbilt Cup. Christie quickly took stock of his resources to find a new car for the races held on 6 October.

The Christie Direct Action Motor Car Company’s 1906 touring car. This car was stripped of its body and modified to race in the 1906 Vanderbilt Cup. Note the stripe painted on the axle.

The Christie Direct Action Motor Car Company had just completed a seven-passenger touring car. With no other car available, it was the only option for the race. Christie quickly returned to his New York shop and removed the touring car’s blue painted body and black leather seats. A new body was fabricated with the seats over the rear axle. The steering was redone and the steering shaft extended. Other efforts were made to lighten the 2,300 lb (1,043 kg) touring car.

The touring car’s radiator was removed and a new one installed. The new radiator was similar to those used in the previous Christie cars but had a header tank at its center. The engine of the touring car was very similar to the original Christie F-head engine from 1903 and to the engine used in the rear of the 1905 car—all had four atmospheric intake valves and one mechanical exhaust valve. It is possible that these three engines were actually the same engine. However, the bore and stroke of the touring car’s engine was increased from the 1903 engine by .375 in (10 mm) and 1.0 in (25 mm) respectively. The touring car’s engine had a 5.375 in (137 mm) bore and a 7.0 in (178 mm) stroke. The engine produced 50 hp (37 kW) at 1,200 rpm from its 635 cu in (10.4 L). The car had a 102 in (2.59 m) wheel base and a 56 in (1.42 m) track. In race trim, the touring car’s weight was dropped to 1,895 lb (860 kg) race-ready.

Christie and his nephew Lewis Strang sit in the race-ready touring car stripped for the 1906 Vanderbilt Cup race. This image was taken at the start of an elimination trial. The stripe on the axle noted in the previous image is just visible.

At less than half the power of most of the other cars in the Vanderbilt Cup, Christie did not stand much of a chance. After running for a while in seventh place, Christie had slipped back to 13th place out of the 18 competitors, averaging 44.7 mph (71.9 km/h) when the race was called. Even so, Christie had shown that his front-wheel drive cars were as reliable and competitive as those of other manufacturers that used a conventional powertrain. After the race, Christie refocused on his V-4 racers.

Christie’s 1906 touring-car-turned-racer was eventually sold to William Gould Brokaw. The car reappeared in March 1908 at Ormond Beach, Florida and was driven by R. G. Kelsey. The racer failed to finish a 125 mile (201 km) race but placed second and averaged 62.4 mph (100.4 km/h) in a 256 mile (412 km) race held two days later. Also, Kelsey covered a mile in 42.8 seconds (84.1 mph / 135.3 km/h). The further activities and ultimate disposition of the racer is unknown.

Christie and Strang taking a turn during the 1906 Vanderbilt Cup race. Although the bore had been increased, the engine could very well be the same as the original 1903 engine.

Sources:
– “The Front-Wheel-Drives of John Walter Christie, Inventor” by Stan Grayson Automobile Quarterly Volume 14, Number 3 (1976)
– “Motor-Vehicle” US patent 761,657 by Walter Christie (granted 7 June 1904) 2.7 MB pdf
– “A New American Automobile” Scientific American (28 January 1905)
– “The First Christie Front Drive Touring Car” The Automobile (13 September 1906)
– “Now for the Selection of the American Cup Team” The Motor Way (20 September 1906)
– “Christie’s New 100-Horsepower Racer” The Automobile (5 August 1909)
– “Florida’s Meet Supplied More Records than Races” by John C. Wetmore The Automobile (12 March 1908)
– http://www.stohrdesign.com/christie-automobiles-1903-1909-a-blog (various pages)
– http://www.vanderbiltcupraces.com (various pages)

By William Pearce

Safely clearing land mines has been a challenge vexing militaries since shortly after the devices’ first widespread use in World War I. Methods to clear land mines have included heavy rollers or flailing chains positioned in front of vehicles and designed to detonate the mines without it damaging the vehicle. In the midst of World War II, the German firms Alkett, Krupp, and Daimler-Benz designed a new vehicle to detonate land mines and clear a path for men and machines to follow.

The strange looking Alkett VsKfz 617 (NK-101), preserved at the Kubinka Tank Museum. Note the small slit in the armor for the driver’s view. The small structure in front of the driver’s window was a position indicator for the rear wheel.  (Kubinka Tank Museum image)

Built in the Alkett factory near Berlin, the VsKfz 617 Minenräumer was heavily armored and designed to detonate mines by simply rolling over them. (VsKfz is short for Versuchs Kraftfahrzeug, meaning “test vehicle.”) The three-wheeled vehicle’s wide track was designed to clear a mine-free path for other vehicles to safely travel. The sole prototype carried the Alkett chassis number of 9537 and was registered as NK-101. Unfortunately, much solid information on this vehicle has been lost to history.

The Alkett VsKfz 617 had two large main power wheels at its front. A smaller, caster-style rear wheel was used for turning. Via power take offs and clutches, turning the steering wheel engaged worm shafts on both sides of the hull. The worm shafts operated in opposite directions—one side drew in a chain while the other slackened a separate chain. The chains extended through the VsKfz 617’s hull and were connected to each side of the rear wheel, rotating it as the driver turned the steering wheel. There is no indication that any differential steering was available.

The rear wheel of the VsKfz 617 digging into the ground can be seen in this image. Note the large shoes of the main wheel.

Each wheel was made up of 10 links and 10 thick, heavy, solid shoes. The pin that connected two links also attached a shoe. Three of the shoes would come together on the ground for each wheel. The total of nine shoes gave the VsKfz 617 ample ground contact. The thick shoes were also resistant to damage from mine blasts. Damaged individual shoes and links could be easily replaced.

The VsKfz 617’s transmission was positioned in middle of the vehicle. A shaft led from each side of the transmission and engaged the gearing for the main wheels. A Maybach HL-120 V-12 engine was situated transversely behind the transmission. This gasoline engine produced 300 hp (224 kW) from its 4.13 in (105 mm) bore and 4.53 (115 mm) stroke cylinders. Its total displacement was 729 cu in (11.9 L). Two radiators were positioned behind the engine. Cooling air was brought in from ducts on the upper middle of the VsKfz 617 and expelled through vents on its upper rear. A 190 gallon (720 L) fuel tank was positioned above the rear wheel.

This poor quality image of the VsKfz 617 still conveys the vehicle’s rather imposing appearance. Only one machine gun is in the turret, which is how it was found by Russian forces.

The VsKfz 617’s hull had about 39 in (1 m) of ground clearance that helped protect the crew from mine detonations. Furthermore, the bottom of the vehicle’s hull consisted of 1.58 in (40 mm) thick armor plating, with an additional 0.79 in (20 mm) of armor sheeting inside—creating a double hull. The rest of the vehicle’s hull thickness varied from 0.39 to 1.58 in (10 to 40 mm).

For defensive armament, the VsKfz 617 prototype had a Panzer I turret with two 7.92 mm MG 34 machine guns. However, the production version would have a Panzer II turret with a single 20 mm KwK 30 L/55 cannon and one MG 34 machine gun. The driver occupied the left side of the vehicle and saw out via a small slit in the upper armor. A rear wheel position indicator was just in front of the driver’s view. The vehicle’s commander was on the right, operating the turret. The VsKfz 617 was 20.6 ft (6.28 m) long, 10.6 ft (3.22 m) wide, and 9.5 ft (2.90 m) tall. It weighed 55 tons (50 tonne).

This view of the VsKfz 617 displays its unique side profile.

Testing of the VsKfz 617 started as soon as it was completed in 1942. It was quickly found that the VsKfz 617’s method for steering was unsatisfactory and that the vehicle was slow and hard to handle. To make matters worse, its immense weight caused the vehicle to easily get bogged down. The VsKfz 617 and plans for its manufacture were abandoned after the tests.

The sole VsKfz 617 was captured by the Russians in late World War II, possibly in April 1945. The vehicle was inspected and tested in Kubinka near Moscow in early 1947. The Russians came to the same conclusions as the Germans regarding the VsKfz 617’s use, also finding that its slow speed and lack of maneuverability would make it an easy target for artillery. The VsKfz 617 was preserved and is currently on display in the Kubinka Tank Museum.

The Alkett VsKfz 617 (NK-101) Minenräumer on display in the German pavilion of the Kubinka Tank Museum. Note the steering chain passing through the hull. The scoops on the top of the vehicle are the cooling air exits from the radiators. (Kubinka Tank Museum image)

Sources:
– http://ww2history.ru/3909-nemeckijj-minnyjj-tral-minenraumer.-nemeckie.html
– http://www.rumaniamilitary.ro/enciclopedia-armelor-roboti-terestrii-in-ww-ii-2
– http://www.taringa.net/posts/apuntes-y-monografias/14137217/Vehiculos-extranos-2gm-Kfz-617-MINENR-UMER.html
– http://strangevehicles.greyfalcon.us/Alkett.htm
– http://www.tankmuseumkubinka.com/?cat=3