Mk1 coach bogie pivot casting

Can anyone explain the purpose of the gasket between the underneath of the pivot casting and the top of the bolster on a BR1 bogie? I wouldn't have expected any galvanic corrosion here. Bolts or rivets join the two components anyway.
Thanks

 

From my experience all bogie centre castings have gaskets fitted between them and the bolster, its not just on MK1 bogies. That extends to LMS, GWR, LNER, LBSCR, SECR, SR, ETC Not exactly sure why it is there but they are quite universally used, usually practises like this evolved through experience.

 

During the process of renovating our Weltrol currently at Newbridge on the NYMR
We visited the NRM Search Engine at York.
Photoing one of the drawings shows the casting with a comment about a Brass sheet being fitted.
No reason given though.
Is this similar to your situation?

Apologies for the file size but I don't want to lose detail.

 

Hi . No it doesn't look the same, The gasket I am refering to is underneath the bottom casting to issolate it from the bolster. In the SRPS you tube video of the buffet car overhaul it shows the guys fitting a fabric or rubber gasket to what looks like a B4

 

Hi Garry. Great photos . Cheers Norman

 

Hi Garry . Great photos . Thanks Norman

 

I've taken a few of these apart and never found any gasket as such. Just some form of mastic that makes them difficult to separate.

I find that, after removing the bolts, a sturdy scraper, hammered under one edge, will separate the two.

 

Hi Ken. I wonder why it would even need mastic ? Might keep water out I suppose if it was around the outside. Maybe it is just as simple as that. The casting i have just removed was riveted.

 

I watched the video concerned, (see below) it looks like some kind of canvas cloth (cotton ?) . I would say it was there to deaden/dampen any vibration when the vehicle is running. As the centre casting will be cast iron it might help deaden vibration and reduce the likelyhood of it cracking too especially when you tighten up the bolts if the bottom of the casting and the top of the bolster are not perfectly flat. Watching the guy trying to cut the hole with a hacksaw blade. Surprised he doesn't just use some strong scissors

The mastic will be there to try and stop water getting underneath and rusting it.



They look to have some nice facilities and doing good work.

 

I've seen a hairfelt used between the centre casting & bolster on a Gresley vehicle.

Bob.

 

The stuff I took out was in poor condition but hair felt could describe it quite well I think .

 

A member of our Weltrol team suggests the pads under the casting may be a form of Noise / Vibration reduction measure.
Does that sound likely?

 

An interesting arrangement of slings at 14+ minutes. Do they do an English Language version of the video?

All of ours have been bolted. You'd need to go back a few years on our Blogs but, when we first set about removing some (damaged-rough shunted) castings, we were cautious of using too much force. However, at that time, one of our Blog followers was a retired Head of C&W, Swindon, then living in Bolivia?, and essentially, his advice was 'hammer a scraper' where they met. And it worked.

I can't remember if it was a 'full bed' of mastic, but certainly more than a 'bead'. And it wasn't the normal BR original red mastic. It was more of a black coloured compound.

As to whether we used anything for the replacement 'repair', I'm unsure. I think it was just bolted back down due to time constraints. Obviously with a 'cast' to 'cast' mating, then some form of 'gasket' (malleable or cartridge, or even just sheet canvas) would be best practice.

 

Thanks Ken. I am about to put it back using bolts and will put some gasket material underneath. Another large railway I spoke to just bolt them up metal to metal with no problem but I think a gasket is preferable.

Thanks all for your help. Much appreciated.