Mk1 Resources And Parts
- Thread starter 28ten
- Start date
Bob Reid
Western Thunderer
28ten
Guv'nor
The postie called this morning with some etches. Unfortunately the etcher had etched through a half etch fold 
however I soldered it up anyway and found a few minor errors for correction in the second revision. one being the slots for the side bolster ( the two vertical lines you can see) i dont know what I was thinking putting them there
Secondly the spring guide has a tendency to rotate but an extra fold will cure that.
The plus is that it works very nicely with .9 piano wire, the spring rate is just about right ie it just provides a little cushioning without acting like a pogo stick.
however I soldered it up anyway and found a few minor errors for correction in the second revision. one being the slots for the side bolster ( the two vertical lines you can see) i dont know what I was thinking putting them there
Secondly the spring guide has a tendency to rotate but an extra fold will cure that.The plus is that it works very nicely with .9 piano wire, the spring rate is just about right ie it just provides a little cushioning without acting like a pogo stick.
Next job is to go thorough the lists....
Dog Star
Western Thunderer
After a visit to Toddington to obtain "encouraging" photos for the Guv'nor.... I went to see the C&W gang at Winchcombe where the shutter button did overtime. Purely in the spirit of ensuring that Cynric is aware of what is what under a Mk.1...
How do you hang yours?
Or, put another way, I do hope that this piece of tin work features on the pending WT-Mk.1 truss.
regards, Graham
PS for Bob... the outboard end of the bracket appears to be secured to the under-side of solebar... the bolt in the picture does not form any part of the fixing for the bracket. Any idea as to why this bolt is there? (maybe something is missing... this is a preserved / restored vehicle and fidelity to prototype is not guaranteed).
How do you hang yours?
Or, put another way, I do hope that this piece of tin work features on the pending WT-Mk.1 truss.
regards, Graham
PS for Bob... the outboard end of the bracket appears to be secured to the under-side of solebar... the bolt in the picture does not form any part of the fixing for the bracket. Any idea as to why this bolt is there? (maybe something is missing... this is a preserved / restored vehicle and fidelity to prototype is not guaranteed).
Dog Star
Western Thunderer
There are something like 25 Mk.1s at Winchcombe... and I found just one with the symmetrical V-hanger, all the rest were asymmetric where present. What I found to be surprising is that (a) all of the vac-cyls are on the same side of the brake cross-shaft as far as I could see... and (b) there appeared to be no correlation between bogie type (BR1 / CW / B4) and the type of V-hanger. This revelation rather upsets the suggestion that BR1 gets symmetric whilst CW / B4 gets asymmetric and that symmetric is vac-cyl outwards of the cross-shaft and asymmetric is vac-cyl inwards of the crosshaft. Of, course, there is no guarantee that these arrangements were either "as-built" or "as-maintained" by BR etc..
Time for Bob (Reid) to explain the story.
I am not sure that I understand this comment, please expand for me.
regards, Graham
Dog Star
Western Thunderer
And just in case there is any suggestion that this arrangement of dynamo support is an one-off... there is another vehicle in the "to-do" pile with a similar arrangement...
A couple of comments for the avid "under the cover" enthusiast:-
(1) the dynamo bracket is not "vertical";
(2) the "prototype" had a plethora of pipes which makes me think that this was a dual-brake example.
regards, Graham
A couple of comments for the avid "under the cover" enthusiast:-
(1) the dynamo bracket is not "vertical";
(2) the "prototype" had a plethora of pipes which makes me think that this was a dual-brake example.
regards, Graham
28ten
Guv'nor
There is an article on Chocolate/Cream Mk 1s and their formations, I have a list of the WR mk1's but the article expands on that
Bob Reid
Western Thunderer
It's (fairly)! straightforward Graham - under BRs ownership symmetrical Vee hangers were used on the early BR bogied Mk1's (which had unequalised brakegear) Asymmetrical Vee hangers were used - from around 1954 - on Mk1s with BR bogies that were fitted with equalised brakegear. both the Commonwealth and B4/B5 equipped vehicles had equalised brakegear from new and therefore had asymmetrical hangers. Unfortuantely preservation vehicles are the worst to use as examples - so much inevitably having been changed - especially when it comes to bogies unless you know it's history. If you can find any photo's in BR days of anything other than the above arrgtss - let me know! Here's a good example of a BR bogied Mk1 with asymmertrical hangers ;
M35218_21-6-59 by robertcwp, on Flickr
That style of bracket supporting the dynamo, didn't change much - there were some minor changes in the fabrication of it however. The bolt you are seeing on the dynamo suspension trimmer (there's a matching one out of site on the opposite side and corner) was for aligning the dynamo to ensure that when the bogie ran in straight line the dynamo belt rant right in the centre of the two dynamo pulleys - there was a risk otherwise that when the bogie turned that the dynamo belt could run off the edge of pulley. The purpose of the chain was to allow the dynamo to be pulled up close to the bogie for fitting a new dynamo belt - it generally was left slack in normal use - not clipped up as seen in that photo.....
Bob.
M35218_21-6-59 by robertcwp, on Flickr
That style of bracket supporting the dynamo, didn't change much - there were some minor changes in the fabrication of it however. The bolt you are seeing on the dynamo suspension trimmer (there's a matching one out of site on the opposite side and corner) was for aligning the dynamo to ensure that when the bogie ran in straight line the dynamo belt rant right in the centre of the two dynamo pulleys - there was a risk otherwise that when the bogie turned that the dynamo belt could run off the edge of pulley. The purpose of the chain was to allow the dynamo to be pulled up close to the bogie for fitting a new dynamo belt - it generally was left slack in normal use - not clipped up as seen in that photo.....
Bob.
Dog Star
Western Thunderer
Parkin pg.14 for plan and elevation, pg.19 for section. I cannot find a photo, in that book, which shows this aspect of the underframe.
regards, Graham
Dog Star
Western Thunderer
Thank you Bob,
Only straight forward when the principle has been explained clearly! What a pity that such comments as yours were not included in Parkin's book.
To make sure that I have this correct... if the brake pull rod from the cross-shaft goes over the top of the bogie headstock then:-
(a) the bogie has equalised brake gear;
(b) the brake cross-shaft is supported in asymmetrical V-hangers;
(c) the vac-cyl (if vac-brake) is outside of the V-hangers.
otherwise, un-equalised brake gear, symmetric V-hangers and vac-cyl inside of V-hangers.
Which kind of means that we ought never to see a Mk.1 with symmetric V-hangers and either B4 or CW bogies.
regards, Graham
28ten
Guv'nor
For my mk 1's I will settle for the upper bits being as good as possible and the underframe being a good representation, they will after all be hitched up behind a loco and moving. Otherwise I might as well have bought 8 MMP mk1's, and having built 3 of them for commissions, im confident they are as accurate as you will get, and less faffing about for the extra details as it they are built in.
Bob Reid
Western Thunderer
It's all a bit relative to how far you want to go and how accurate they need to be for any specific coach at any given time - without a doubt though the MMP Mk1s would be a good starting point however there's room for improvement there also (should you want to take it that extra mile) but it would be extremely difficult and costly) to include all the possible variations over the years in one single kit and many of which are relatively unseen in normal circusmstances.
Bob.
Bob.