Perhaps the most striking feature of the M103 heavy tank was its massive turret, in which the commander and gunner sat far to the rear. The bore evacuator on the 120mm gun is visible near the muzzle. Details of the running gear are revealed here, including the five shock absorbers. A handrail was welded to the turret side below the ventilating blower.
This front view showcases the cast elliptical hull similar to the 90mm gun tank M48. Round headlight brush guards are present, although the lights themselves are absent. The apertures for the two coaxial machine guns are visible on each side of the main gun, and the armored housings for the M14 rangefinder can be seen on each side of the turret. Lifting and towing eyes are on the extreme front of the hull.
A towing pintle is centered on the bottom of the hull rear plate, with towing eyes on each side at the extreme bottom. Lifting eyes are just inboard of the fenders at the top of the rear plate. Normally there would be attachments for the gun travel lock and an infantry interphone box in between the lifting eyes, but these are absent. Transmission access was granted by the plates surrounding the towing pintle as well as the grille doors on the rear deck visible sloping downwards towards the camera. Taillights/brakelights are just inboard of the final drive housings. The large bulge in the turret rear is for the ventilating blower housing, and two smaller antenna mounts were welded to the turret rear and right-rear.
The engine exhaust was provided with deflectors to prevent heating of the gun travel lock, and the mounting points for the turret bustle exhaust deflector can be seen above the exhaust outlet. The main engine access grille side door is facing the camera, and the main engine access center grille doors are in front of and behind the exhaust.
The extreme rear position of the gunner can be ascertained by the bulge for his seat in the turret bustle bottom. One can imagine that the gunner especially appreciated the turret's engine exhaust shield when it was installed! The right-hand main engine access grille side door can be seen, and the exhaust port for the auxiliary engine exits from the front of this door. When in service, the auxiliary engine would have a muffler mounted on the fender.
This tank is fitted with with the small driver's hatch, meaning it is one of the first sixty produced. Three periscopes M26 or M27 provided forward vision when buttoned, and the hatch cover has a mount for an infrared periscope M24. The fitting to the driver's right was a hookup for the exhaust pipes of the two personnel heaters (mounted in each front corner of the hull), and the small cover on the hull roof to his left rear is where the bilge pump outlet could be mounted.
The commander's cupola M4 allowed the .50cal machine gun to be aimed and fired from under armor, although unlike later cupola designs the commander had to unbutton to reload the weapon. Four periscopes M17 were provided in the cupola. The turret ventilating blower is in the foreground, and the cupola is facing the rear of the turret.
A bore evacuator and cylindrical counterweight were mounted at the muzzle of the 120mm gun. Early counterweights featured two large holes to also act as blast deflectors, but due to ineffectiveness at attenuating target obscuration and concern over the deflector failing at the holes, the front of the deflector was removed, like on this example.
The drive sprocket is highlighted here, along with other suspension components including the rear return roller, road wheels, and shock absorber. The final drive housing can be seen; the final drive spur gear ratio was 7.077:1.
The gun travel lock is stowed on this vehicle, but when in use it swiveled upward and was supported by two legs attached to the hull rear plate on early tanks, and later vehicles added a third leg which was attached to the rear deck. (Picture courtesy Armor Foto.)
This vehicle is actually the first pilot T43, the pre-production model of the M103. As such, it is not fitted with the production cupola that provided remote-control fire for the .50cal machine gun, but rather one that is identical to the cupola on the M47 tank. The front loader's escape hatch and hold-open latch are visible in the foreground. To the right of the commander's cupola in the image is the turret ventilator dome, and the gunner's periscope guard is on the other side of the cupola. The gunner's periscope is actually part of a removable turret top plate that runs laterally across the turret roof and longitudinally from in front of the commander's cupola to behind the loader's hatch.
The impressive bulk of the machine becomes apparent when its crew is available for scale. Note the taller engine air cleaner on the rear fender amidst the stowage boxes, indicating this vehicle is powered by the diesel engine. (Picture from Tank Data, volume 2.)
The tank's elliptical hull design is easily seen in this imposing view. In the right-hand headlight group we can see a small blackout marker light and a large blackout service headlight. A regular service headlight would occupy the space beside the blackout marker light, and the tank's horn would be positioned in the upper V-shaped guard between the headlights. On the the tank's left side, the blackout service headlight and another blackout marker light are present, with a blackout drive light in the V-shaped space above the blackout marker light. The service headlight would again occupy the outboard position.
A handrail is visible on the turret side, and a stowage rack lines the rear of the turret, interrupted by the stowage mount for the gun shield-mounted searchlight. An air cleaner for the diesel engine is mounted on the tank's fender. By this stage, remote control operation of the .50cal machine gun had been eliminated, and the commander's cupola had been redesignated M11.
Like the tank directly above, the personnel heater exhausts are present on this tank and routed to the driver's right, and the bilge pump outlet is fitted to his left. The driver was also provided with the larger hatch. The bulge in the turret for the gunner's former position is easily seen on this tank, although he was moved forward in the M103A1.
The exhaust on this tank is vented through M60-style louvres instead of through a port in the rear deck. This redesign necessitated a new gun travel lock, which is in use on this vehicle. The towing pintle is obvious in the center of the rear hull, and above and to either side of this are transmission access plates. Taillight guards are to the outside of the transmission access plates.
Modifications to the tank commander's cupola are visible here compared to the early style on the tank at the top of the page. This latter style did not offer the option of firing the machine gun while buttoned. The structure directly in front of the TC's cupola is a vane sight that assisted the commander in targeting the 120mm gun. The new position of the gunner can be ascertained by the location of his periscope, which is now in front of the turret hatch (the periscope opening in his former position has been blanked off). The receptacle opposite the gunner's periscope was for providing power to the searchlight.
The driver's controls are shown here. The steering wheel is similar to that found in the M48 tank. The tachometer is to the left of the steering wheel, and the speedometer is on the opposite side. The transmission selector lever is visible to the right side of the picture, and the accelerator and brake pedals are on the driver's right and left, respectively. The headlight dimmer switch is just to the left of the brake pedal.
When in reverse, steering the wheel counterclockwise would result in the tank's rear swinging to the right; a leftward movement of the rear was performed by turning the wheel clockwise. Turning the wheel to the right or left while the vehicle was in neutral would cause the front of the tank to pivot to the right or left, respectively.
The driver's accessories control panel was placed to his left, and projectile and charge stowage racks are visible behind the panel. Ammunition stowage was placed on both sides of the driver.
This picture was taken from the driver's compartment looking back into the turret. The breech of the 120mm gun M58 takes up most of this image. The gunner's instruments are visible to its right, and ammunition charge stowage is visible on the opposite turret wall.
The floor of the turret basket is the subject of this image. The two tubes on the basket floor to the left in the picture are the elevation motor generator and the traverse motor generator and accessory box assembly. Hull ammunition stowage can also be seen to the extreme left of the image.
More details of the stowage on the turret's left side are visible here, as well as a seat for the left loader. The box to the front of the turret was for .30cal machine gun ammunition.
The gunner's and loaders' hatch is visible in the turret roof here, and the gunner's position and controls are to the right of the 120mm gun's breech. The M14E1 ballistic computer is on the bottom to the front of the gunner, and a browpad for his sighting instruments is visible near the turret roof. His periscope is missing from this vehicle, however.