View Full Version : Operation Trinity and the Baillie Beam

24-06-2011, 11:42
Operation Trinity was the attack on the German warships Scharnhorst and Gneisenau at Brest from December 1941, using electronically equipped Stirlings. 7 Sqn from Oakington took part.

The method has been described as the forerunner to Oboe, but was actually closer to the Luftwaffe's X-Gerat system.

There was a Baillie Beam transmitter at Helston, providing the track, and the CHL station at West Prawle was used for 'release', working with the IFF set in the Stirlings.

The beam was 'invented' by George Baillie at Farnborough and was a precise version of the Lorenz / Standard Beam Approach system. It was probably similar to the later RTG/J Beams (http://www.airfieldinformationexchange.org/community/showthread.php?3205-Radio-Track-and-J-Beams)

Anyone have any further information, in particular the location of the Helston device?

EDIT: name changed from Bailie to Baillie.

24-06-2011, 21:13
possible site, Predannack/Mullion/Drytree is not far from Helston?


25-06-2011, 15:53
My feeling is that the Bailie Installation would be quite remote from other radio /radar sites to avoid beam bending / distortion caused by the proximity of other aerials in the vicinity.

The set-up.

26-06-2011, 09:55
my udder half asks if you know the height of the Brailie Beam antenna as she can work out the deflection from a Chain Home antenna using the height and the operating wavelength.... its all to with ripples and yogi bear apparently :-D (radio geeks don't you just love them!)

26-06-2011, 10:35
Some thing else that has come to mind, wasn't West Prawle abandoned as a CHL site?... I am sure I read an article in which the writer was dismayed at the way the National Trust had bulldozed the CHL site at Coleton Fishacre to make a car park, in the article it said the site replaced West Prawle in 1940.

26-06-2011, 12:48
Some thing else that has come to mind, wasn't West Prawle abandoned as a CHL site?...
Yes I'm sure it was. Unfortunately I've just discovered that the Helston Beam was quickly relocated to Bolt Head. Nothing is simple - which is why research is so interesting.
One source I have says RV Jones was directly connected with the project and his initial meeting was at West Prawle. There is absolutely nothing in his 'Most Secret War' about any of this.

28-06-2011, 09:13
Its a bit like peeling an onion, soon as you get one layer off there is another and just cant help wanting to know what's under that layer too :roll:

Predannack was briefly home to a radar training/research unit a couple of times early on in WW2 if that is any help.

29-06-2011, 15:18
More confusion:

RAF Beam Benders - No.80 Signals Wing (Laurie Brettingham) has further information.

F/Lt George Baillie (double ll in the name) worked for the Scientific Analysis Section of 80 Signals Wing (no mention of Farnborough),then worked for Radio Warware Establishment at Watton after WWII.
He engineered the Baillie beam which later became the 'J' Beam. (see above link). The Baillie Beam was reckoned to guide an aircraft to a small target 125-150 miles away at a height of 10,000 feet.

The aircraft equipment, christened 'Broody Hen' was very unreliable needing constant retuning with a screwdriver - which was great fun when the pilot was diving around avoiding the defences. During operations cetain radars in the UK had to be switched off to avoid interference.

The enemy soon worked out how the RAF had got reasonably accurate with the bombing and installed heavy defences on the approach. Was that why the beam was moved from Helston to Bolt Head.