Wellingtons and sono-buoys (High Tea)

[ThomasP]

First operational tests of pre-production 'High Tea' by 210 Sqn supposedly took place in Jun/Jul'42, using Sunderlands out of Sullum Voe, Shetlands. 210 Sqn had (I think) officially transitioned from Sunderlands to Catalinas by this date, but possibly used a couple of available legacy Sunderlands for the tests? I have no idea if these 'High Tea' units were the US made CRT-1 series.

The UK first ordered 1000x CRT-1 sonobuoys and 30x R-2/AAR-3 receiver sets in Oct'42.


This is what I have for the CRT-1 series:

AN/CRT-1, Ø4.75" x 48"L as dropped, 14 lbs, 6 channels in 67.6-71.7 MHz 'Black' band, audio detection at 300 Hz to 8K Hz
in service 43

AN/CRT-1A, Ø4.75" x 44"L as dropped, 12.7 lbs, 6 channels in 67.6-71.7 MHz 'Black' band, audio detection at 100 Hz to 10K Hz
in service 1944

AN/CRT-1B, Ø4.75" x 45" as dropped, 13.5 lbs, 12 channels in 62.9-67.9 MHz 'White' band, audio detection at ?
in service 1944

Individual shipping tubes were either Ø5.25" for the CRT-1 & -1A or Ø5.5" for the CRT-1B (no idea why the difference).

NOTE the above dimensions and specs are from various manuals. However, I think there were a couple of different aerial sections that saw service - possibly of different length - which would result in different overall 'as dropped' lengths.


R-2/AAR-3 was usable with 67-72 MHz 'Black' band CRT-1 and -1A sonobuoys

R-2A/AAR-3 could receive both 'Black' & 'White' bands from 62-72 MHz.

As of Sep'49 the AN/CRT-1A/-1B series buoys with R-2A/ARR-3 receiver system was designated ARI.5286 in UK service.

 

[WATU]

First operational tests of pre-production 'High Tea' by 210 Sqn supposedly took place in Jun/Jul'42, using Sunderlands out of Sullum Voe, Shetlands. 210 Sqn had (I think) officially transitioned from Sunderlands to Catalinas by this date, but possibly used a couple of available legacy Sunderlands for the tests? I have no idea if these 'High Tea' units were the US made CRT-1 series.

The Sunderland trial really interests me. Blackett outlined his idea for a sonobuoy but the whole project was then passed to the US given the huge pressure British development resources were under. I have not spotted anything about a British device being designed during the war. So if 1942 trials happened they are highly likely to be a very early stage RCA AN/CRT design. Is it in the 210 ORBs or was it a 210 aircraft assigned to CCDU maybe? You don't hear of CCDU having dedicated flying boats (I think) so perhaps when needed they borrowed an operational one at a normal operational base. Was a formal CCDU report done in which case there is a good chance it is at TNA in AVIA7/1418. I have bits of that file but nothing relevant.

The rest of what you listed looked fine.

 

[WATU]

210 sqn ORBs for May-Aug 1942 offer no evidence. From web searches the squadron changed from Sunderlands to Catalinas from July 1940 to April 1941 ish. From the ORBs the main missions in summer 1942 were to Russia and other long range patrols unsuitable for Sunderlands. Does not seem any reason for the odd Sunderland to be held with issues of spares, ground crew, etc.