Kerrison Predictor

Damien Allan · #1 31-05-12, 02:54

Hi Neil,

in answer to your questions, the Kerrison could only be used with the powered mounts. The power units were referred to as hydromotors and they bolted onto the rectangular plates in front of the traverse and elevation geartrain. There was also a lot of other gear that had to be incorporated into the gun mount. In Australia, all powered mounts were converted back to hand cranked by removing the hydromotors. These mounts often retain some of the other parts like the electrical junction box near the equilibrators,the traverse indication gear under the platfrom and the drive input shafts that connect the hydromotors to the gun mount gearboxes.

I have seen a couple of guns with the hydromotors connected, but I think they were probably reinstalled by the current owners. I have two spare sets of the hydromotors in the shed myself (anyone interested?), so they are probably a few more out there. There are some good photos of Bofors in North Africa, all fitted with hydromotors.

If the battery wanted to engage more than one target multiple Predictors would be required. The intention was that a battery of guns can be operated from a single Predictor, which would be impressibe to see.

Does anyone out there know where a copy of the Illustrated Parts List for a Kerrison might be? I know they exist, as I missed out on one a few years ago. I recovered a Kerrison in its transit case from a barn in Bathurst NSW 10years ago, but the farmer had used it as a source of bits and pieces over the years. I don't think too much is missing (scopes are still there), but the IPL will tell me for sure. Also keen to locate a Kerrison tripod, cheers D

Neil Ashley · #2 31-05-12, 10:29

Damian

Thank you for the reply.

When you say power units/hydromotors, I assume you are refering to the electric motors rather than a generator?

Do have any info on what generator was used for this purpose?

Damien Allan · #3 04-06-12, 13:38

Neil,

Yes, I am referring to the electric motors rather tha the generator.

I have not seen (to my knowledge) a generator in Australia, but there is a good article on them by Kim Siddorn at http://www.wessex-sec.co.uk/2007%20N...rs/Jul07p2.pdf

There is a good often published picture of a Kerrison aimed Bofor battery in the south of England waiting for V1s. There may be a glimpse of the generator in that - I will have a look and see if there is a better picture reference in case you do not know the picture I mean.

cheers,

Damien

Neil Ashley · #4 28-02-13, 21:32

Quite an old thread but I found this picture today of a UK based Bofors Gun still fitted for powered laying via a Predictor.

Presumably quite rare in this unmodified configeration.

George Moore · #5 01-03-13, 15:30

If anyone is going to, or lives near(ish) to Woolwich, the Firepower Museum at the arsenal has a library.....pre arranged visits are required, contact Paul Evans (paule@firepower.org.uk), or phone 020 8312 7125.

I was researching detail of the 3" 20cwt AA gun used early WW2....in the box file was an IPL for a predictor......the 3" was also coupled to a predictor, some photographs show cables running into the base, and a set of photographs taken of the Egyptian Army show a gun with predictor.

I had a quick look through the IPL, I was more interested (from a modelling point of view) to get the dimension drawings, however there were only two photographs of the overall shape, but pages and pages of bits and pieces.

May be of help, not sure. The photocopying fees are very reasonable, and they always welcome a small donation. Very helpful people too.

Here is one photo of the Egyptian gun with predictor.

George.

easo · #6 02-03-13, 00:56

G'day all, does anyone have an image of the larger predictor described above?

Easo

Tim Bell · #7 02-03-13, 19:35

I have a manual entitled:

Notes on Repairs to Fire Control Instruments - Part 1

Predictors, A.A, 3-in. No 1, Marks II to VII

1941

Second Edition

Is this the equipment you are referring to?

Tim

Godwin Hampton · #8 10-03-13, 13:40

Quote:

Originally Posted by Damien Allan

I have seen a couple of guns with the hydromotors connected, but I think they were probably reinstalled by the current owners. I have two spare sets of the hydromotors in the shed myself (anyone interested?), so they are probably a few more out there. There are some good photos of Bofors in North Africa, all fitted with hydromotors.

Damien,

Do you still have the Hydromotors? Where are you located?

Regards

Godwin Hampton

Damien Allan · #9 17-03-13, 12:29

Hi Godwin, and hello all of the Kerrison correspondents.

I do have a spare sets of T&E motors which are available. I am in Sydney - contact 0419 230 043. Also I have spare elevation gearboxes including hand cranks for anyone who needs those.

I have been lucky to acquire a Kerrison in transit case with optics ex-barn in Bathurst. It has a few parts missing, and I will have to remanufacture them most likely. That said, I am looking for the No.3 Predictor Illustrated Parts List (to work out what is missing), and the whole No.3 predictor tripod.

I noted previous references in this thread to getting the M5 manual on line, but I have not been able to find it myself. Anyone have a current link?

Looking forward to hearing from anyone who can assist.
cheers,

Damien

PS. No.3 MkI Predictor for Kerrison is different to the 3in No.1 predictor. The No.1 series were for Vickers made for mainly 3.7in AA. They are heavy and densely packed with gears and cams. Japanese predictors were based on the Vickers commercial models that came out between the wars - would be happy to collect one of those too.

Godwin Hampton · #10 24-03-13, 17:34

Damien,

You are halfway round the world from my neck of the woods! I'm in Malta, Europe - so getting hydromotors over would probably cost an arm and a leg! My Bofors can be seen at http://www.anti-aircraft.co.uk/Malta_Bofors.html

The outriggers are not mine and I am looking for a pair, or at least the jacks. I have 6" tubing to make up the arms, so if you have a pair of jacks....

Could you post some pictures of what you have available? Or write me.

Best Regards

Godwin