Tangmere knock

This may seem like a silly question

But Tangmere seems to have a knocking sound to it.
What is it?
Just a worn rod?

I think its quite characteristic. 8)

 

The motion on un-rebuilt Bulleids in particular were known to clank around quite a bit, and was indeed one of their trademarks. However, the sound is probably accentuated by the fact that things get a little looser the more something is used. All the same, I like the sound myself (I must admit, when I first saw the title of this thread, as I have been up in Llangollen for three days without access to a computer, I thought there had been an accident caused by a heavy shunt, that is, until I opened the thread!)...

 

As a child of the late '50's my memory of live steam was that they always clanked so it seems very authentic to me.

 

Tangmere's "clank" has got more pronounced in the last year. It is most noticeable when working hard at low speed. I video'd her Torbay Express run at the end of September last year, and was quite worried about her. It dominates the soundtrack of my shots of her slipping to a stand at Broadsands at lunchtime, and climbing to Greenaway tunnel in the late afternoon. (See Steam Age Pictures Volume 25: Mainline Album 2008, Part 3: SR Locomotives.) I wasn't so aware of it when filming her on The Great Britain a couple of weeks ago, so maybe some work was done to improve matters last time she visited Carnforth?

 

As far as I am aware Bulleids have a clanking sound to them at low speeds anyway. Part of their Charm! Although it could be issues with Tender wheels/axles? Has anyone been close to work out where it is coming from or any video footage of the exact Clanking sound?

 

I don't think unrebuilt Bulleid Pacifics are any more prone to developing rod "clank" tendencies than any other type of locomotive. Those with plain bearings take an awful lot of mechanical punishment!

What I've noticed from Tangmere at low speeds is a pronounced metallic sound accompanying two of the 6 "chuffs". I believe this emanates from the chimney so could be associated with exhaust ports or valves.

All supposition of course... :-k

John.

 

Hi all
My first mailing as the new boy on shed.
In my day, it was common to hear (and feel) a heavy bump on the footplate of an unrebuilt bulleid. This was from the inside big end.
Cheers
Sir Hectimere (ex 73A)

 

Interesting. That probably explains what I felt and heard on the footplate of 34081 when on the Moors.

 

The exhaust beats from the inside cylinder are more pronounced then the others. This is because the valve is directly under the blastpipe, and being outside admission there is a very short and direct flow for the exhaust compared to the outside valves.

The clanking is usually side play - clearance - in the connecting rod big end - which is normal - combined with a slightly out of true crankpin which causes the con rod to move across the gap twice every revolution.

 

Well, my guess wasn't far short of the mark! Thank you for your explanation, bringing knowledge and experience to NatPres as always!

John.