Experimental, USA, WWII

T18 Boarhound: a 30-ton Armored Car

The T18 Boarhound was a massive 8×8 armored car developed by the United States during the Second World War. It was longer than a Sherman and had almost as much armor. In fact, when it was first conceived, it was more heavily armored than any German tank.

It had good offroad performance, but its size and weight ultimately led to its downfall.

Fortunately, a single example of this rather unknown vehicle still survives today.


T18 Boarhound’s Development

During the fall of France and the early African campaign, the UK had been impressed with the German 8×8 heavy armored reconnaissance vehicles, and wanted to try and mirror these vehicles in British service.

However the British were also under no illusions that their own manufacturing capability was extremely bottlenecked. It was already working at full capacity replacing what had been lost, and there was little time for new concepts with an invasion at the door, so it began to look to its allies for vehicles. 

The UK, though facing shortages and doing its best to turn out as much as it could, asked the US for help acquiring a medium or heavy multi-wheeled armored car for use in North Africa.

Sd.Kfz. 231 armored car.
Germany’s 8×8 armored cars, such as the Sd.Kfz. 231-series were fast and had excellent off-road capabilities.

Conveniently, the US was also wanting a series of light, medium and heavy armored cars so this was approved.

Also conveniently, a vehicle had already been developed in the US during this period, by the Trackless Tank Corp – sometimes called Trackless Tank Company online.

This firm had been developing wheeled vehicles since the late 30s, focusing its time on producing an 8×8 machine as part of a private enterprise rather than to an ordered requirement.

It had not been designed with cross-country reconnaissance in mind, but they had been running tests in 1940 with a turretless hull. Although met with some scepticism from the Army and Ordnance branches – who tended to be wary of anything new – it proved capable enough for a second look at Aberdeen in March 1941.

T13 Armored Car trials.
The American 8×8 T13 armored car.

Following this a contract was signed for 2 further prototypes, built and paid for by the US Army under the name T13.

This unusual vehicle had garnered some interest from the US as well as Canadian, British and Australian onlookers. All who saw the demonstrations were impressed with its cross-country capability and saw merit in the independent suspension systems it sat on.

But the US and UK voiced concerns over the weight, crew layouts and the company’s limited experience in large-scale military projects. T13 would end up getting a small turret that contained a 37 mm gun and was renamed to T13E1, yet as time passed it became increasingly clear to the US army that T13 was not going anywhere fast despite an initial desire for 1,000 vehicles.

T13E1 with 37 mm gun.
T13E1 with the 37 mm gun turret.

Pressure was applied for the firm to merge or partner up with somebody who knew what they were doing, yet even after the company had been more or less forced into merging its vehicle with others, including the Huber Co., Mack Manufacturing Co. and finally REO, there were too many fundamental flaws and eventually the project was cancelled. 

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Yet the idea had sparked interest, as when it became obvious early on that the Trackless Tank Corp was going nowhere, officials pushed for a parallel project that could be put out to other American firms for a medium and heavy armored car as a backup.

These alternative vehicles would be given the numbers T17 and T18, the Staghound and the Boarhound.

T17 Staghound.
The T17 Staghound was a powerful and very capable vehicle. However its size meant it was impractical for reconnaissance missions.

On the Boarhound front two vehicles were planned: the T18 and the T18E1.

The former was to be in an 8×8 configuration and the latter a 6×6. A wooden concept model was made before any working concepts were produced, with this being enough for the placement of a large contract.

The initial order placed on December 24 1941 was for 2500 units, to be delivered by June 1943. But this was quickly changed to 2500 units by December 31, 1942 in a following letter issued just 3 days later. In March 1942 another order for 300 more T18s was placed.

Plans for the 8x8 T17.
Plans for the 8×8 T18.

The contract was placed with the Yellow Cab Division of the General Motors company. The numbers and timescale was somewhat alarming to the company, as it felt it would take 6 months to get the parts, tools and jigs in order, leaving just 5 to 6 months to complete 2500 vehicles.

This would be equate to about 500 per month, or around 500,000 lbs of material use a day.

The firm felt that it would be better to produce a smaller batch, growing in number per month at an upsold value to the UK so that any issues could be weeded out as they progressed.

Yet this was soon revised again with a lower estimated number of 5 vehicles being ready by September 1942, and by December production would be up to 50 vehicles a month, a lot less than the proposed 500 planned.

T18E1 Boarhound mock-up.
Wooden mock-up of the T18 Boarhound.


The original vehicle was designed as an 8-wheel drive, 4-wheel steering armored car with a 37 mm gun and a coaxial .30 caliber machine gun in a 360-degree power-operated turret. 

A further .30 caliber machine gun would be mounted in a ball in the hull.

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Each vehicle would carry a crew of five: three in the turret and a gunner and driver in the bow.

Protection would be 50 mm on the hull front and about 82 mm around some parts of the turret face. The side armour was 31 mm on the sides, 25 mm on the rear and 19 mm on the top and bottom.

.30 caliber bow machine gun.
.30 caliber bow machine gun in a ball mount.

This was very thick for an armored car of its day, with comparable armor to the 30-ton Sherman tank.

The original spec called for two GMC 329 petrol engines delivering 250 hp in total (125 hp each) in the rear of the hull, running through automatic transmissions to the 8 driving wheels.

This arrangement would produce a top speed of 50 mph (80 kph) over reasonable ground.

UK tests recorded the engines as 127 bhp and a top speed of 51.5 mph achieved after 17 seconds.

T28E2 rear.
To appreciate the size of the Boarhound, the vehicle immediately to its right is a T-55 tank.

Transmission-wise, one engine was connected to the first and third axle, the other to the second and fourth axle. On normal ground only the rear four wheels would be powered, but should wheel slip occur automatic pick-up drives would connect giving the vehicle 8×8 traction.

Good cross-country abilities were achieved through freely articulated suspension systems in which any wheel on one side can be raised by 20 inches or any complete axle by 18 inches without changing the weight on any other axle.

Responsive steering would be obtained by turning all four front wheels with a power steering system.

T18E2 suspension close-up.
The T18E2’s suspension system.

All of this led to a pretty chunky vehicle, in fact for her time she had more armour than many tanks, considerably more than the German panzers, and was much heavier than many British tanks.

At just over 6 meters long, 2.5 meters tall, 3.7 meters wide and weighing 30 tons, the T18 Boarhound was, for a reconnaissance vehicle, anything but stealthy.

The initial T18 prototype came with an American 37 mm gun, which was fairly standard for the time. This weapon was mounted on many US vehicles of the period and was more than adequate for dealing with other armoured cars and quite capable even against the early panzers found in North Africa.

Driver and co-driver viewports.
Driver and co-driver viewports.

It did however lack a useful high-explosive capability. This gun was fitted into a small Rockwell-type turret, similar to that on the T17 Staghound.

In early 1942, the British changed their mind on some of the specifications, notably around the main armament. They now wanted a 6-pounder, or 57 mm, gun to match the changes in enemy armor and tank developments in the UK.

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This would of course require some major rework on the T18 boarhound, now renamed T18E2, as not only would it need a new turret – which would be a reworked turret from the M7 medium tank – but the internal fittings would need to be adjusted for the new ammunition.

T18E2's turret.
The T18E2’s turret. It was derived from the failed M7 tank project.

Trials and Cancellation

However, this delay in up-gunning the T18 Boarhound would also help spell its own doom as the retooling and changes would delay production further.

The first prototype would not be out until October or November of 1942, although this particular vehicle had a shorter and stumpier 57 mm gun that was also found on the T7E2 tank.

Later examples would all have the longer, tapered 57 mm M1 gun types.

But the T18 Boarhounds’ fate was rapidly approaching. The US Ordnance no longer showed interest in the vehicle as a reconnaissance machine so they began wrapping the project up. By November 1942 they had no interest in pursuing the vehicle at all.

The T18E2 Boarhound.
The Boarhound with the shorter 57 mm gun.

However, the British were still somewhat keen to get the vehicles they had paid for (quite how much they paid in total is not recorded).

In an AFV situational report written in February 1943, it was recorded that some 29 vehicles were on the production line and that a further 58 hull and 90 side armor casts had been produced and that perhaps it might be worth finishing these for a complete unit to be operational.

The T18E2 from the side.
The T18E2 with the longer 57 mm gun.

This matter was passed to the Director-General of Fighting Vehicles, but does not appear to have been approved as only 30-odd vehicles would ever be finished. Yet even by August 1943 the British army staff in America were still receiving and producing guide and maintenance books for the T18 Boarhound. 

These vehicles would be produced in dribs and drabs until May 1943, with varying numbers shown as ready in official sources.

However, this does immediately disprove the notion that the Boarhounds were all sent out to Africa and took part in convoy duties and fought battles out there, as the German Africa Corps had surrendered in early May 1943, by which point the T18s were still stuck in the US.

Boarhound prototype.
The T18 wouldn’t see any service and was only trialled before it was cancelled.

So no, Boarhounds did not see action in North Africa.

Come 1944 and the UK was still testing their T18 at Chertsey.

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Overall these British trials went fairly well, despite being nearly a year after the order had been canceled.

The notable issues found were the brakes were inadequate, and would quickly overheat. The hill climbing was reportedly acceptable, albeit not as good as some other armored cars, and there was a tendency to wheel spin if it was forced to do a hill start.

Boarhound entry hatches.
The crew’s side hatches. Note the externally-mounted lever above the side hatch to open the front viewport.

The transmission was found to be persnickety and prone to playing up, and was difficult even for trained fitters to locate and find the root of problems. 

Other problems were minor and fixable; corrections to the driver seat, towing eyes being too weak, and the fuel drums straps broke, etc., all quite solvable problems.

One thing that was recorded was the turning radius, which was 78-79 ft – this is very large, nearly 25 meters or so – which would have made the vehicle nearly unusable in some areas. Yet despite being recorded there didn’t seem to be any undue criticism of this.

T18 Boarhound left side view.
The Boarhound’s sheer size would have made it impractical in many areas, such as in European towns.

The UK trials were stopped in November 1944, and simply recorded that no further action was to be done with the Boarhound and the vehicle was to be disposed of. 

Today the boarhound still leaves us with many questions.

Exactly how many were made? And how many ever reached the UK? We know at least 1 did in testing, and a Boarhound is seen at both the Lincoln and London victory celebrations, yet whether it’s the same one is not certain.

T18 Boarhound today.
The T18E2 Boarhound today inside the Vehicle Conservation Centre at The Tank Museum in Bovington.

To date, there are no known photos of more than one T18 Boarhound in any single photo.

Today only one vehicle is known to exist, it is kept in the Vehicle Conservation Centre at The Tank Museum in Bovington.

Which vehicle this is remains a bit of a mystery as sadly over the years it had a lot of paint slapped over it and any original markings have vanished.

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One can only hope that it still has the original serial number plate left inside.