Braking bits

I knew the the combined knowledge that resides here wouldn’t let me down.
I will test you all again with some more of the pile of bits, some which I’ve identified and some which stubbonly refuse to be indentified in the Horsa or Hamilcar APs that I have.

Thanks again chaps.

The forum at its best, hope all goes well with the project.

regards Dave

Pleased to have been of some assistance!

Dave and TwinOtter, many thanks that’s brilliant, just what I was after.
The slots in the inner drum was the detail that was missing from my understanding of how these brakes worked.
What I’m missing (apart from the friction material on the shoes) is that inner drum and the return spings. What I do have is both axles and two wheels and I’m trying to get the curator’s permission to install the port mainwheel on to the Hamilcar fuselage at Wallop although that will mean mocking up the oleo (unless someone has one of those ;))

Interstingly the pilots notes describe the action of releasing the pressure from the oleo as ‘Raising the the undercarriage’ when a more accurate description would be ‘Lowering the fuselage’.

The chances are that some of the pieces I am cataloguing belonged to this Hamilcar which had this slight mishap on the airfield where they were burnt and buried.
[ATTACH]182834[/ATTACH]
No persons were seriously hurt for this photograph although the Tank crew were more than a little shocked. Yes they were passengers. 😮

Possibly similar to how DC3 brakes attach?

Does this help in any way? :confused:

As Bruce says make sure you do your asbestos RA.

My experiance of these things is that they work a little like an old brake shoe system on a car, only this is a drum within a drum, the inner drum is fixed and has the air connection to the bladder on it. The bladder then sits around the outside of this drum and the shoe fits astride the bladder with the tabs on the back going through slots in the drum then the bits of shaped steel that you have fit in the slots in the shoe and a spring fits central between the metel and the drum to hold the shoe off when not in use hope this makes sence. As for the number required if you have the inner drum then the number of slots will give you the number of shoes.
l have used masking tape on the pads to hold the fibres while l work on them maybe you have a different method hope this helps

regards Dave

Thanks for the warnings and advice guys.
As for asbestos I think there is little chance, as I said the parts have obviously been burnt before burying and during this the copper rivets melted and left the linings behind; I didn’t dig the stuff up and its also had a pressure wash blast to get rid of some of the soil.

Identifying the parts using the APs is all part of the fun but Middle Wallop only have an incomplete photo copied set of the illustrations fro the Hamilcar AP and anything on the Brakes is missing. So if anyone has a more complete set I’d be interested.

Pneumatics as a power source for aircraft systems was quite popular with the british aircraft industry in the 30s and 40s which I only really became aware of when I got the chance to work on a Dh Dove which had pneumatic flaps, undercarriage and brakes (discs so no help here) the only hydraulics were the propeller pitch and the windscreen wipers!

Pneumatic bag brakes must have been a common system as I remember reading numerous acounts of their weaknesses and foibles but I’ve never seen any details of their workings.

Thats an interesting system

I spent many years doing brake relining for cars and trucks plus brake bands for cranes etc, but what you have there Aeronut is new to me, But will agree with Elliot that it would be almost certainly a Dunlop system. It certainly looks weird enough for them. Jaguar cars used to use Dunlop brakes , really strange setup. Lockheed were the main brake people but all hydraulic. Hope that helps

Aeronut

Have you looked in the aircrafts AP? There are often drawings of the wheel assemblies including the brakes. Your brake shoes look like Dunlop designs to me – the other option is to contact them – they have a very large archive but charge or at least did when I last spoke with them about 8 years ago!

Be very careful with burnt brake shoes – there will be a lot of loose asbestos dust. Sorry if I am teaching you to suck eggs – but its no less dangerous than the radioactive instruments we’re all so , err, fond of!

Bruce