Editor's note: After coming back from TravellerCon US, I want to broaden my scope a bit, but still focus on the original intent. To help people recognize when I'm going off-topic, anything not connected to WW1 or the Interwar period will have the Other Wars title.
So the blog's been up for a few days now, and I've been checking in fairly regularly. It's been reassuring to see that there are visitors; there's always a bit of fear, I think, that an author is the only person interested in their topic. One thing I like with this is that it tracks general information on who's visiting - lots of Americans, the UK second, Canada and Germany tied for third. And then, in a tie for fifth, there's Australia. Australia gets forgotten about when discussing armor, probably even more than Canada does (the T2K Facebook group had a nice discussion about Ram tanks, Kangaroos, and Skinks just recently). So, while it's a little outside this blog's stated remit, I have a remedy.
Early in World War II, Australia and New Zealand were concerned about a Japanese invasion and a lack of available tanks from England (who was...well, rather busy with that Austrian chap). So, they decided to take matters into their own hands. As much as I was tempted to go Kiwi and stat out the Bob Semple, I have enough of a sense of self-preservation to not encourage my friends from the Southern Hemisphere to hunt me down. Instead, I'd like to discuss the AC1 Sentinel.
The Sentinel was originally intended to be a cruiser tank of no more than 20 tonnes, developed from the American M3 Medium in the same way as the Canadian Ram. However, it grew into a medium tank of 28 tonnes bearing much less resemblance to the M3. Due to a lack of adequate powerplants, it used three engines (Cadillac V8s of 110 horsepower each). Intended to mount either a 2-pdr or a 6-pdr, the lack of 6-pdrs meant they were armed with the smaller 40mm QF 2-pdr. Vickers machineguns were mounted coaxially and in the hull. The only service the Sentinel saw was serving as German tanks in the 1994 film The Fighting Rats of Tobruk. Units survive at Bovington, Puckapunyal, and Cairns.
AC1 Sentinel
Fire Control: 0
Stabilization: None
Armament: QF 2-pdr in turret, Vickers Mks 4-7 in turret, Vickers Mks 4-7 forward
Ammo: 130x40mm, 4250x7.7mm
Fuel Type: G, A
Veh Wt: 28 tonnes
Crew: 5 (commander, gunner, loader, driver, hull machinegunner)
Mnt: 14
Night Vision: Headlights
Tr Mov: 96/58
Com Mv: 22/13
Fuel Cap: 590
Fuel Cons: 240
Config: Veh
Susp: T: 6
HF 20
HS 9
HR 9
TF 20
TS 20
TR 20
QF 2-pdr
Rld: 1 Rng: 380
KEAP: Dmg: 9 Pen: 6/5/4/3
HE was never produced, but would have been C:2 B:9 Pen: Nil
Variants:
The AC1B was to carry a 25-pounder gun. It was never built, as the decision was made to build the AC3 instead, but an AC1B would have been a vicious little thing. To make room for the larger ammunition, the hull machinegun and gunner were removed.
Armament: 87.6mm L/28 Ordnance QF 25-pdr, Vickers Mk 4-7 in turret
Ammo: 120x87.6mm, 2500x7.7mm
Crew: 4 (commander, gunner, loader, driver)
QF 25-pdr
Rld: 2 Rng: 285
HE: C:8 B:19 Pen: 6C
KEAP: Dmg: 19 Pen: 23/20/17/11
Ah the Bob Semple tank... remarkable for what they achieved but people shouldn't get upset if the "tank" is described in unflattering terms - after all, they didn't really know what they were doing when they built it.
ReplyDeleteIt never would have been particularly good despite what the patriotic fervour of later generations would like to hope.
A far better design from New Zealand was the Schofield light tank (specifically the second proto-type).
Did you know that during research for the AC3 Thunderbolt, one Sentinel vehicle was fitted with a turret mounting two 25-pdrs to see if the turret could withstand the increased recoil of the 17-pdr proposed for the AC3?
Two 25-pdrs! That could be an interesting vehicle.
Something else about the Sentinels, while they never served in combat, they did get used extensively as training tanks. At the time production was to be instituted, large numbers of armoured vehicles were able to be sourced from the USA so it was decided that there was no longer a need to produce tanks in Australia.
All joking aside, it was impressive that the Semple was able to be put together, and it shows the desperation of the people, realizing no help could arrive from Britain.
DeleteI was aware of the twin 25-pdr, but there was never any intent to use it that way. It wouldn't have been effective, since the extra space for the second cannon took up room for the crew. I didn't do a 17-pdr variant because that turret ended up with a larger ring than the AC1 had.
I wasn't aware that the Sentinels were used for training. With American vehicles arriving, it was felt that it would be better for Australia to focus on producing logistical vehicles (particularly rail engines) and allow the Americans to focus on combat vehicle production.
Ah my apologies are in order as it's obviously been months since your reply. Yes the twin 25-pounder would have been completely impractical as a combat vehicle for the reasons you mentioned. The problem being that I have a strange fascination for the impractical concept of "land warships" so tanks with multi-gun turrets are like candy to a sugar-fiend!
ReplyDeleteIn regards to the Sentinels being used for training, I had heard this when I was in an Armoured Recce Regiment of the Australian Army but the only specific reference I can now find to it is a comment from Australian Sentinel and Matildas. AFV/Weapons Profiles 31 by James Bingham that states that the tanks were in use until 1956 for training purposes as mentioned on this page (under the title Australian tank program) http://military.wikia.com/wiki/Tanks_in_the_Australian_Army#CITEREFBingham1972
Things get confusing however as other online sources declare that the tanks were being disposed of in 1946 however a newspaper article from 1946 states that the Disposals Commission was unable to interest civilian buyers in the tanks when they were offered for sales.
Newspaper article http://trove.nla.gov.au/newspaper/article/62868169
All in all, the whole story makes for some interesting reading and hopefully one day the correct details will be available online!
As an aside, the Sentinels were also used for the Australian 1944 movie The Rats Of Tobruk masquerading as German panzers apparently, although it's been so long since I saw that movie I could not tell you if that's correct or even how much screentime they get.
On the assumption that you haven't seen them, the following pages are reasonably informative as well: -
http://www.mheaust.com.au/Aust/Research/Sentinel/sentinelmk.htm
https://thearmoredpatrol.com/2017/02/26/australian-ac-tanks-part-i-ac-1-sentinel/
https://s3-ap-southeast-2.amazonaws.com/awm-media/images/collection/pdf/RCDIG1070361--1-.pdf