P2 Locomotive Company and related matters

I’m not sure how you would turn a tyre unsupported by a wheel - nor indeed why you want to do so.

Looking at them in the photo, I’m not convinced they have been turned in any case: they still look a slightly rusty colour and don’t appear with a bright finish in comparison to those on the adjacent loco.

Tom

 

On a VTL, or a centre lathe on a backing plate.

Predominatly because as bought they looked like rough blanks and not semi-finished tyres, which they now appear to be.

Look a lot brighter to me than the initial picture. Look at the flanges, they are actually profiled now as opposed to a 45deg chamfer.

 

Yes, you might be right - not very clear picture on my phone.

I’m curious as to why you would part finish them though, given that it will be years hence before they would be needed. I’m sure there must be a reason.

Tom

 

Machine time? Two birds? Whilst the P2 has a machine time booked make the most of the opportunity?

Could be a semi finish to within .250/.500 tho? Then it’s just a skim to put them on DWG size when they are assembled? Machine time now is cheaper than machine time in a few years? Pure guesses here...

 

How about rough machining for flaw detection and to allow for them to stress relieve themselves over a period of time?

 

No, that’s not a thing. Heat treatment is used to resolve residual stresses.

Possibly for NDT, nice to know they are flaw free.

 

Maybe things are different with steel, but Myford cast iron lathe beds were rough machined and then left outside for 6 months or so to let any stress within the casting relieve itself.

 

It might be a residual stress thing. If you carve great lumps off a bit of billet/forging, you will get some distortion. Roughing out to plus a few millimetres (remember too, you need to do two operations to machine the job all over), then finishing in two separate operations allows you to remove any distortion. Used to work this way on jet engine shafts, though admittedly they are slightly closer tolerances.

 

Perhaps they just shined them up with a bit o wet and dry because they looked scruffy...

 

In the image, they really look machined, not just polished - note how even the reflections are.

I was guessing they went down with 2007's wheels and tyres, but I don't see them on the trailer on the way back? (Odd the way they seem to have switched from a short truck+trailer at the start to a long truck at the end...)

And yes, SDRE can machine tyres off the wheel. So good to see SDRE accumulating such a nice group of machine tools (e.g. the boiler plate press); it's so good for vintage rail world to have that resource.

Noel

 

What really strikes me is the extreme little clearance between the wheels and the frame!

 

From when I used to work as relief on the Wheel lathe and other machines at BREL York.
All wheelsets were for coaching stock with the odd outside job including some small loco wheelsets.

Wheelsets came in for retyring, put on to a lathe and had the gibson ring removed, then into the fire to remove the tyre.
Once removed the outer surface of the wheel disc was then skimmed to a constant diameter.
The disc was then measured up and the new tyre then had its inner face machined to suit the disc.
This was carried out on a horizontal bed machine with the outer face of the tyre fully in contact with the lathe bed. Tools were applied from the inner side working down into the tyre.
On completion then the wheelset went to the Wheel lathe for profiling.

Added stages were also carried out if the Axle needed to be removed from the disc or if the journals needed to be rolled out or even skimmed on the journal lathe.
After the Wheel lathe then the wheelsets went for balancing.

 

Green Arrow is just down the road at Shildon.

 

Come on everybody.Keep up!
https://www.p2steam.com/category/news/

 

To save everyone looking through the website, the answer to the wheel tyres and chimney is here:
"In January 2018, the Trust revealed that it had acquired and taken delivery of a complete set of fully-certified tyres for the new Gresley class V4’s pony, Cartazzi and 5ft 8in driving wheels. They were purchased from David Buck, owner of Thompson class B1 4-6-0 No. 61306 Mayflower, along with a chimney,........... The tyres were originally manufactured in South Africa in the late 1990s for Malcolm Barlow, a Doncaster scrap dealer who launched the Gresley V4 Society in 1994 to build a new example of the class. David Buck acquired the parts six months ago in a job lot of items that Malcolm Barlow had salvaged from Doncaster Works on its closure – including a number of class B1 components."

 

No need; see post #2020, just up-thread.

Noel

 

Can we just admire the sheer size and beauty of no. 2007?

 

Absolutely stunning!

Who could imagined this in 1968?

Thanks a lot for posting this photo aron33!

regards,
Knut

 

This is the first opportunity that anyone has had to stand back from 2007, and appreciate its true proportions.
It really is a beautiful piece of work. What a crowd-puller it is going to be.

 

Nobody, because by 1968 no P2 (let alone an original one) had existed for 24 years at that point. The rebuilt locomotives had all been scrapped by that point too.

There's very few people alive who would remember the originals and probably none who remember 2001 as built.

I only regret that A1 Trust stalwart Malcolm Crawley is not around to see this. I remember his words to me in 2008 when Tornado was on test at the GCR - that he'd never see a new P2 - I was more optimistic, I did not know he was ill at the time. Realising the context of his words in hindsight makes me sadder still.