M18 Hellcat Tank Destroyer 1943–97

This extract is taken from the chapter “Into Combat”.The Tank Destroyer Center wished to deploy the T70 76mm GMC into combat as soon as possible to get feedback about its performance, so two T70 vehicles were shipped to the 601st Tank Destroyer Battalion and three to the 894th which were operating in the Anzio beachhead. The new vehicles arrived at the beginning of May 1944 and their crews were quickly trained by Ordnance personnel in time to take part in the break-out operations which began on 23 May 1944. After inspecting the T70 76mm GMC, the 894th Tank Destroyer Battalion commander decided against deploying them alongside the M10 3-in. GMC, believing that their weak armor would make them too vulnerable. Instead, they were deployed in the battalion’s reconnaissance company, where their high speed was felt to be more useful. In general, the battalion was very happy with the M18’s excellent automotive performance, despite the poor hill-climbing of early vehicles, and its difficulties in mud due to low ground clearance. The battalion found that the M18 could be driven at speeds up to 60 miles per hour and that the high speed “enables the vehicle to cross exposed ground quickly and gain cover without offering a good target. It eliminates wastage of time getting into firing positions.” The battalion was also impressed with the performance of the 76mm gun, though there was some concern that its construction was not as durable as the M7 3-in. gun in the M10. The light armor of the M18 bothered the battalion to the extent that “the crews have much less confidence in the T70 than they do in the M10 and this might easily be reflected in the efficiency and determination with which the crew functions in a firefight.” The battalion was also concerned about the relatively small interior space of the M18 compared to the M10 noting that, “the space inside the T70 is so limited that the crew cannot live in it as they have had to do many times in the M10. Furthermore, the limited space inside the fighting compartment allows only a very small clearance between the base of the (ammunition) round and the back of the turret while loading the piece, making loading more difficult and of necessity much slower than in the M10. Less ammunition can be carried on the T70 and the ammunition is stowed in such a way that only nine rounds are readily available and after firing nine rounds the remainder must be taken from less accessible compartments in the sponsons. Because of the confined space the gunner himself has to get out some of the ammunition on his side of the vehicle.” The battalion concluded in its report that the T70 was an excellent reconnaissance vehicle, “but it is believed to be not as good a weapon for use as a tank destroyer against enemy tanks as is the M10 because of the many limitations pointed out above.” In many respects, this evaluation echoed the earlier comments by General Palmer of the Special Armored Vehicles Board who had warned Bruce and the Tank Destroyer Center about the impact that the focus on speed and mobility would have on other aspects of the vehicle’s performance.In January, Bradley’s First US Army headquarters in England were informed that the M18 would be available in time for operations in France. At first they refused them, stating that they saw no advantage in replacing the M10, and expressing concerns over the additional logistical burden of a new type. Instead, they wanted to wait until the M36 90mm GMC became available. In the event, some battalions arrived in the European theater equipped with the M18, earmarked for Patton’s new Third Army. But their reluctance to accept the M18 meant that fewer entered combat service in Europe than might otherwise had done so.