Royal Marines AA Units on Ceylon in April 1942

[Rob Stuart]

I am attempting to confirm how many AA guns there were on Ceylon at the time of the Japanese air attacks of 5 and 9 April 1942. One of the AA units present was the 1st HAA Regt RM, apparently with B, C and D Batteries. The regiment belonged to 1 Mobile Naval Base Defence Organization (MNBDO). Some sources say there was also at least one RM LAA battery on Ceylon at the time, this battery possibly being 22 LAA Bty RM or even Devon LAA Bty RM. Can anyone comfirm this? Also, how many guns were RM HAA and LAA batteries supposed to have?

Thanks,

Rob

[Gary Kennedy]

The overall organisation for an Army Heavy AA Regt was a RHQ and three Btys, each Bty with two Tps of four 3.7-inch guns apiece. The Light AA Regts underwent some changes in 1942, initially having an RHQ and four Btys, each of three Tps of four 40-mm guns apiece. That altered to an RHQ and three Btys, each of three Tps of six 40-mm guns apiece during the latter part of 1942. I don't know how far off the Army WEs the RMs were though.

You may have already seen this info but there's a good attempt to disentangle the histories of the various RM units -

http://www.royalmarinesmuseum.co.uk/uni ... ies-part-3

Gary

[Rob Stuart]

Gary,

Thanks for your helpful reply. I had previously looked at the RM unit histories but I'm going through it more carefully now, and looking at my other sources, and should soon have a fairly detailed response to post. In the meantime, I have a question:

The Light AA Regts underwent some changes in 1942, initially having an RHQ and four Btys, each of three Tps of four 40-mm guns apiece.

The LAA Regt establishment you give here would add up to 48 guns. My information is that the LAA regiments normally had only 36 guns. Am I mistaken?

Rob

[Gary Kennedy]

Good question, I can't give a specific answer, but I suspect it's a case of the number of Btys. In Armd Divs the LAA Regts were based on three Btys, while in the Inf Div it was four, but outside of Divs they may have gone for three Btys of 12 guns each. In that case, your 36 guns would be spot on. I'm afraid I'm not as well versed with the non-Div units, but within the Divs the 18 gun Bty appeared in the latter half of 1942. If you can confirm three Btys within the unit you're looking at, I think that would explain it. I'll have a check if any of the Defended Ports Abroad WE titles give a number of guns, but I'm not too hopeful...

Gary

[Rob Stuart]

Gary,

The two Royal Artillery LAA Regiments in Ceylon when the Japanese attacked were:

-43 LAA Regt, with 181, 183 and 196 Batteries and a total of 36 guns
-55 (Devon) LAA Regt, with 163, 164 and 165 Batteries, and a total of 36 guns

Both arrived at Colombo on 4 March '42. 43 LAA Regt was on convoy DM 3, whose three ships had left the UK on 12 January in WS 15, but I'm not sure if 55 LAA Regt was in DM 3 too, but it must have left the UK in January (or earlier) to reach Colombo on 4 March.

Would you agree that these two units would have had four-gun troops in April '24?


Thanks,

Rob

[Gary Kennedy]

Sounds spot on to me, the only other option is two Troops of six guns each, but that's not an organisation you see until late 1944 in NWE, so I'd go with four guns per Tp, three Tps per Bty and three Btys in the Regt.

Gary

[Rob Stuart]

Gary,

One of my challenges here is reconciling the list of AA units in Ceylon with the number of guns reportedly on the island at the time the Japanese attacked. There are two sources which give overall numbers:

-the History of the Royal Regiment of Artillery, Anti-Aircraft Artillery 1914-55 says that there were 112 AA guns in Ceylon - 4 x 3 inch, 3 x 12 pounders, 32 x 3.7 inch, and 73 x 40 mm

-a 1943 “Battle Summary” produced by the Admiralty says that there were 110 AA guns – 42 heavy and 68 light

I think that both of these sources are probably wrong. My theory is that is that the RM heavy guns were undercounted and the RM light guns were not counted at all, and that there were in fact as many as 144 AA guns - 52 heavy and 92 light, manned by the following units:

HEAVY GUNS

14 AA Bty of 6 Coast Regt RA, with 4 x 3-inch guns
65 (The Manchester Regiment) HAA Regt RA (with 181, 183 and 196 Batteries), with 24 x 3.7-inch guns
1st RM HAA Regt (with B, C and D Batteries), with 24 x 3.7-inch guns

Total: 52

LIGHT GUNS

22 LAA Bty RM, with 16 x 40mm guns
43 LAA Regt RA (with 147, 148 and 264 LAA Batteries), with 36 x 40mm guns
55 (Devon) LAA Regt RA (with 163, 164 and 165 LAA batteries), with 36 x 40mm guns
3 x 12-pdr, manned by an unspecified unit, possibly 2 HAA Regt of the Ceylon Garrison Artillery (CGA)
1 additional 40mm gun, manned by one of the above units

Total: 92

My evidence, from primary documents held by the UK National Archives and other sources, is as follows:

(1) By December 1937 four of the 12 AA guns authorized for Ceylon had been issued. These were almost certainly 3-inch guns.

(2) On 3 September 1939 the Ceylon garrison included 6th Heavy Regiment RA, at Trincomalee, with two batteries of coast defence guns and 14 Anti-Aircraft Battery, RA. This battery undoubtedly had the four 3-inch guns.

(3) At some point prior to December 1941, the 2nd AA Regiment of the Ceylon Garrison Artillery (CGA) was formed, with 1st, 2nd and 3rd Heavy and 4th Light AA Batteries. By 5 April 1942 they probably had very few men and very few guns. I would speculate that they manned the three 12-pounder guns and maybe some AA machine guns but perhaps nothing else until later. (1st Regiment CGA was a coast regiment and manned the 9.2-inch and 6-inch guns at Colombo.)

(4) A 2 January 1942 ORBAT for “Trincomalee Fortress”, which I think includes in-place units plus reinforcements about to arrive, includes the following:

A.A. Bde. M.N.B.D.O. [Mobile Naval Base Defence Organization - a Royal Marines unit]
One Heavy A.A. Regt (24 guns) [1 HAA Regt RM]
One Light A.A. Bty (16 guns) [22 LAA Bty RM]

(5) On 15 January the War Office advised Wavell that convoy WS 15, from the UK, was carrying 55th LAA Regt, which was a mobile unit, and 65th HAA and 43rd LAA Regt’s, both of which were static units. It added that the LAA Regts were all three-battery units. (Upon entering the Indian Ocean, WS15 split into three convoys: WS 15A, WS 15B and DM 3.)

(6) On 1 February convoy AJ.1, consisting of City of Paris and Yoma, arrived at Colombo from Aden. City of Paris was carrying 1375 MNDBO personnel, apparently including 1st Royal Marines Anti-Aircraft Brigade HQ and 1st Royal Marines Heavy Anti-Aircraft Regiment. The latter consisted of B, C and D Batteries [and, I think, 22 LAA Bty RM]. In February the Brigade HQ was re-designated HQ AA Ceylon.

(7) A 3 February signal from OC Troops Ceylon giving his current ORBAT lists the following AA units:

Colombo

HQ MNBDO
One Heavy [AA] Bty MNBDO [probably has 8 x 3.7inch]
One Troop Light [AA] Bty MNBDO [probably has 8 x 40mm.]
14 AA Bty 6 Coast Regt [presumably still with 4 x 3inch]
HQ 2 AA Regt CGA and one Bty without guns

Trincomalee

Regt HQ MNBDO [presumably the HQ of 1 HAA Regt RM]
Two Heavy AA Bty MNBDO [probably have 8 x 3.7inch each]
One Light AA Bty MNBDO, less one troop [probably has 8 x 40mm.]

(8) On 12 February “22 LAA Battery RM” deployed to Trincomalee’s China Bay airfield, according to the ORB of 273 Sqn, which was at China Bay. (At most there would have been 8 x 40mm guns, since one troop was sent to Colombo.)

(9) On 16 February the War Cabinet Joint Planning Staff in London recommends the diversion to Ceylon of the following from convoy DM 3, which was then due to arrive in the NEI on 4 March

1 Hy A.A. Regt (24 guns)
1 Lt A.A. Regt (36 guns)
1 A/Tk Regt (48 guns)

… and the diversion to India and Ceylon of the following from convoy DM 4, which was then due to arrive in the NEI on 9 April:

2 Hy A.A. Regts (48 guns)
2 and 1/3 Lt A.A. Regts (84 guns)

On 18 February the British Chiefs of Staff ordered the diversion of DM 3 as recommended. The heavy AA unit was undoubtedly 65 HAA Regt but it’s not clear if the light AA unit was 43 LAA Regt or 55 LAA Regt.

I have no information on the AA units in DM 4 – I don’t know which units they were, where they went or when they got there – but probably none of them arrived in Ceylon by 9 April.

(10) On 23 February London advised the Australian government that by 28 February there would be 52 heavy and 64 light AA guns (a total of 116) in Ceylon, with more on the way.

The 52 heavy guns would presumably be the 4 x 3-inch of 14 AA Bty RA, the 24 x 3.7-inch of 1 HAA Regt RM, and the 24 x 3.7-inch guns of 65 HAA Regt RA.

The 64 light guns are harder to account for. If they were counting 22 LAA Bty RM, with 16 x 40mm guns, and whichever 36-gun LAA Regt was expected to arrive on 4 March, that would be only 52 guns. The difference of 12 guns could be accounted for by one more LAA battery. Or there was a muddle and whoever compiled these numbers thought that the two LAA regiments had 24 guns each: 24 + 24 + 16 = 64. Or there was some other reason altogether. (I expect that no one in London was counting the three 12 pounders.)

(11) On 4 March Convoy DM 3 arrived at Colombo. The C-in-C Eastern Fleet diary says the AA units carried by DM 3 were the 43rd Light and 65th Heavy, which is consistent with the information about DM 3 noted above in the minutes of February COS meetings. The History of the Royal Regiment of Artillery says that 43rd and 55th Light Anti-Aircraft Regiments both arrived on 4 March, each with 36 x 40 mm Bofors guns. CinC India’s 28 February signal 4357/G 28/2 says that Wavell planned to retain the 43rd Light and 65th Heavy in Ceylon and use 55th mobile light in India.

(12) On 31 March the Joint Planning Staff in London issued a report which says there were 52 heavy and 52 light AA guns on Ceylon. I think that there were indeed 52 heavy AA guns but more than 52 light AA guns.

(13) At Trincomalee on 9 April, 55 LAA Regt’s 163 Bty had 6 killed and 43 LAA Regt’s 264 Bty had two killed, according to Commonwealth War Graves Commission information. This would confirm that these two batteries, and by extension the rest of their regiments, were on Ceylon.

(14) On 14 April the HQ of the Australian forces then on Ceylon promulgated a list of code names covering all units and formations in Ceylon. The AA units included in the list were:

2 A.A. Regt, C.G.A.
1 A.A. Regt, RM
65 Hy A.A. Regt, RA
55 Lt A.A. Regt, RA
163 Lt A.A. Bty
164 Lt A.A. Bty
165 Lt A.A. Bty
43 Lt A.A. Regt, RA
147 Lt AA Bty 43 Regt RA
22 Lt A.A. Regt [actually 22 LAA Bty]

A similar code name list issued on 26 April includes the following:

2 A.A. Regt, C.G.A.
1 A.A. Regt, RM
B Bty, 1 A.A. Regt, RM
C Bty, 1 A.A. Regt, RM
D Bty, 1 A.A. Regt, RM
22 Lt A.A. RA [22 LAA Bty RM]
43 Lt A.A. Regt, RA
147 Bty, 43 Regt RA
148 Bty, 43 Regt RA
264 Bty, 43 Regt RA
55 Lt A.A. Regt, RA
163 Bty, 55 Lt A.A. Regt, RA
164 Bty, 55 Lt A.A. Regt, RA
A Tp, 164 Bty, 55 Lt A.A. Regt, RA
B Tp, 164 Bty, 55 Lt A.A. Regt, RA
165 Bty, 55 Lt A.A. Regt, RA
65 Hy A.A. Regt, RA
181 Bty, 65 Hy A.A. Regt, RA
183 Bty, 65 Hy A.A. Regt, RA
196 Bty, 65 Hy A.A. Regt, RA

(15) On 2 May Admiral Layton, who was C-in-C Ceylon, advised Churchill that there were 62 heavy and 100 light AA guns on Ceylon at that time. This is 10 more heavy and 8 more light AA guns than I’ve estimated were present on 5 April. This could indicate that additional weapons had been found for 2 AA Regt CGA between 9 April and 2 May, or that my information is incorrect. I have not yet been able to access any of the war diaries of the AA units concerned and hope then when I do this discrepancy can be resolved.

Any comment or observations on the above would be most welcome.


Thanks,

Rob

[Rob Stuart]

FYI, I also posted my 7 January post at http://www.j-aircraft.org/smf/index.php?topic=13297.0 and there have now been 35 responses. AHF members are of course welcome to check out that thread and comment (here or there) if they wish.

Cheers,

Rob

[joven2013]

Just to say thank you for this post/stream. My father (who is still alive) had great pleasure in reading the information posted. As a member of MNBDO, he served in the AA in Trincamalee in Ceylon in the period discussed, but as he said "I didn't even know all these other guns existed! - we thought we wre the only ones".