|
Cruiser Tank Sentinel AC1 |
|
|
|
|
In 1939 Australia's armed forces hadvirtually no modern tanks and lackedalmost any form of heavy engineeringbackground to produce them; even anautomobile industry was lacking.Nevertheless the Australian governmentrealized that it was unlikely thatany large amounts of heavy war matérielwould be available to Australia fromoverseas, and so set to to produce itsown. Among the requirements weretanks, and as there was no local expertiseon the subject one engineer wassent to the United States and an experiencedengineer was obtained from theUnited Kingdom.With this experience to hand the Australianarmy staff issued a specificationand Australian industry set to witha will, The first design, known as theAC1 (Australian Cruiser 1) was to havea 2-pdr (40-mm/l,57-in) gun and two7.7-mm (0,303-in) machine-guns, and itwas decided to use as many componentsof the American M3 tank aspossible. The powerplant was to comprisethree Cadillac car enginesjoined together and extensive use wasto be made of cast armour. A secondmodel, to be known as the AC2, wasmooted, but by late 1941 as theJapanese became increasinglyaggressive in the Pacific, the AC2 waspassed over in favour of the existingAGI, which had armour ranging from25 mm (1 in) to 65 mm (2,55 in) in thickness.The first AC Is were ready by January1942 and were soon named Sentinel.The whole project from paperworkrequests to hardware had takenonly 22 months, which was a remarkableachievement since all the facilitiesto build the tank had to be developedeven as the tanks were beingbuilt. But only a few AC1 tanks wereproduced as by 1942 it was realizedthat the 2-pdr gun would be too small tohave any effect against other armourand anyway, the hurried design stillhad some 'bugs' that had to be modifiedout of the design. Most of thesebugs were only minor, for the Sentinelturned out to be a remarkably sounddesign capable of considerablestretch and modification. This was justas well, for the Sentinel ACS mounted a25-pdr (87.6-mm/3.45-in) field gun barrelin the turret to overcome the shortcomingsof the 2-pdr.The 25-pdr was chosen as it wasalready in production locally, but itwas realized that this gun would haveonly limited effect against armour andthe Sentinel AC4 with a 17-pdr (76.2-mm/3-in) anti-tank gun was proposedand a prototype was built. This wasduring mid-1943, and by then thebackground to the hurried introductionof the AC1 into service had receded.There was no longer thechance that the Japanese might invadethe Australian mainland and anyway,M3s and M4s were pouring off theAmerican production lines in suchnumbers that there would be morethan enough to equip all the Allies,including Australia, Thus Sentinel productioncame to an abrupt halt in July1943 in order to allow the diversion ofindustrial potential to more importantpriorities.The Sentinel series was a remarkableone, not only from the industrialside but also from the design viewpoint.The use of an all-cast hull wasway ahead of design practice elsewhere,and the ready acceptance ofheavy guns like the 25-pdr and the17-pdr was also way ahead of contemporarythought. But the Sentinel serieshad little impact at the time for theexamples produced were used fortraining only.SpecificationSentinel AC 1Crew: 5Weight: 28450 kg (62,720 lb)Powerplant: three Cadillac petrolengines combined to develop 246 kW(330 bhp)Dimensions: length 6.325 m (20 ft 9 in);width 2.768 m (9 ft 1 in); height 2,56 m(8 ft 4,75 in)Performance: maximum speed48.2 km/h (30 mph); range 322 km (200 miles); trench 2.438 m (8 ft)
|
