Some thoughts about the railway

[RRU]

Hello everyone. It`s been quite some time since I last posted anything but I have been here reading the other posts, none of which I have been able to reply to.

 

So I decided to start this thread. I would like the panel's opinion as to whether or not they will be willing to reply to my comments, some of which may be controversial.

 

Also, as I have both comments and some questions, I would like to know if I could post them all here as I don't want to start two separate threads because they are all linked together

But I do not want to incur the wrath of Mr. Moderator.

 

I will be interested in your replies.

 

Peter

[sir douglas]

depends what the questions are

[The Johnster]

I think we can probably take on a bit of controversy, Peter, as long as the inevitable polarising of opinions does not become disrespectful or judgemental.  Everyone is entitled to their viewpoint, but everyone else is entitled to their opinion of it; gentlemanly behaviour is essential and aggression must be avoided, no matter how passive.

 

True scale modelling is an impossibility and this is a hobby of compromises.  In 4mm, even 'finescale' this is necessary to make things work with any degree of reliability and to get functional layouts in to limited spaces (even Pete Waterman could do with more space!).  We are a bunch of compromisers putting ourselves away as scale modellers, and I work in coarse scale 00 using tension lock couplings and setrack curvature in the fiddle yard.  Nobody knows everything, and anyone who thinks they do probably knows nothing, but we have amongst our contributors some very experienced real railwaymen and modellers whose views should be given due respect.

[RRU]

3 hours ago, The Johnster said:

I think we can probably take on a bit of controversy, Peter, as long as the inevitable polarising of opinions does not become disrespectful or judgemental.  Everyone is entitled to their viewpoint, but everyone else is entitled to their opinion of it; gentlemanly behaviour is essential and aggression must be avoided, no matter how passive.

  

 

I have no intention to upset anyone, none of my posts are personal or aimed at any individual. 

 

My inquiry is whether I am posting in the correct group. The heading is Discussions not questions,  but my posts will be asking for an opinion from railway staff rather than hard technical ones.

 

Just to let you know where I am coming from.

I have worked in the bus and coach industry as a mechanic since 1962 and driving part time since 1970 so some of the working practices of the railway differ to what I am used to.

This is what I would like to discuss.

 

Peter

 

Edited August 17, 2019 by RRU
Spelling mistake

[rob D2]

Go on then spit it out .....;)

[John-Miles]

Whatever you do, don't say anything critical about P4. Apparently it has reached perfection.

[RRU]

1 hour ago, John-Miles said:

Whatever you do, don't say anything critical about P4. Apparently it has reached perfection.

Ah yes, the track, we may as well start there and work upwards.

 

Has there been a change to the track gauge or wheelsets back-to-back measurement?

I ask because I have never heard as much squealing from flanges as ther is now.

All trains passing through York make a terrible noise exept The Scarborough Spa Express which just glides through.

 

Any ideas?

 

Peter

[Edwin_m]

1 hour ago, RRU said:

Ah yes, the track, we may as well start there and work upwards.

 

Has there been a change to the track gauge or wheelsets back-to-back measurement?

I ask because I have never heard as much squealing from flanges as ther is now.

All trains passing through York make a terrible noise exept The Scarborough Spa Express which just glides through.

 

Any ideas?

 

Peter

The wheel and track dimensions haven't changed significantly (new track was 3mm narrower for a couple of decades then went back to the traditional 1435mm). 

 

But my own theory is that you may be hearing the consequence of modern bogie dynamics. 

 

Above a certain speed any rail vehicle will zigzag from side to side as it runs along the track, known as hunting.  This was analysed in the 1960s by British Rail Research and to counteract it most trains built from the 1970s onwards have dampers (shock absorbers) that resist the rapid rotation of the bogie that takes place during hunting.  These can be seen mounted horizontally outside the bogie frame on many types of rolling stock, with brackets attaching one end to the bogie and the other end to the body.  However these have the side-effect that the bogie doesn't line up as exactly with the track on curves, so there is more flange squeal. 

[RRU]

11 hours ago, Edwin_m said:

The wheel and track dimensions haven't changed significantly (new track was 3mm narrower for a couple of decades then went back to the traditional 1435mm). 

 

But my own theory is that you may be hearing the consequence of modern bogie dynamics. 

 

Above a certain speed any rail vehicle will zigzag from side to side as it runs along the track, known as hunting.  This was analysed in the 1960s by British Rail Research and to counteract it most trains built from the 1970s onwards have dampers (shock absorbers) that resist the rapid rotation of the bogie that takes place during hunting.  These can be seen mounted horizontally outside the bogie frame on many types of rolling stock, with brackets attaching one end to the bogie and the other end to the body.  However these have the side-effect that the bogie doesn't line up as exactly with the track on curves, so there is more flange squeal. 

 

Thank you Edwin_m. That is a very good answer. It explains why the Commonwealth bogies under the Mk 1 coaches just roll round the curves.

 

But could I just say this. In my experience of suspension dampers, once they have been moved to a new position they then stay there until they are moved again. So you would think that when the bogie has turned into the curve there would be no force on it until the curve straightens out again. Or are these dampers self-centering?

 

Peter

 

[jim.snowdon]

It does have a lot to do with bogie dynamics, or rather different manufacturers/designers approaches to solving the problem of bogie stability at high speeds. The difference is not so much the presence of yaw damping but the yaw stiffness of the primary suspension and the effect that that has on the angle of attack between the wheel and rail. German bogies, in particular, have tended to be very stiff in this respect, and correspondingly noisier, with higher lateral contact forces. The practical demonstration is listening to the Siemens 360 stock in and out of Paddington - painful by comparison with the Bombardier 387 and 345 stocks using the same platforms. It also affects wheel and rail wear and a modification to at least some of the Siemens stock on the Wessex route was to soften the longitudinal stiffness of the primary suspension.

i had the same experience on the DLR years before, when it was possible to compare the behaviour of both the German designed P stock, and the Bombardier designed B stock, especially through the crossings at West India Quay. The first had high side forces and was trying to escape sideways at every crossing whilst the second were distinctly tamer. I went one step further and had one set of bogies modified, with assistance from Bombardier (who had a first class bogie designer), with primary suspension that would allow the wheelsets to passively steer round curves, after the manner of some of the earlier tramcars suspensions. It worked well, but we decided that by comparison with changing the tyre profile (fairly radically) the additional expense wasn't justified, largely because of issues to do with the underfloor wheel lathe.

 

Jim

[jim.snowdon]

25 minutes ago, RRU said:

 

Thank you Edwin_m. That is a very good answer. It explains why the Commonwealth bogies under the Mk 1 coaches just roll round the curves.

 

But could I just say this. In my experience of suspension dampers, once they have been moved to a new position they then stay there until they are moved again. So you would think that when the bogie has turned into the curve there would be no force on it until the curve straightens out again. Or are these dampers self-centering?

 

Peter

 

Yaw dampers, at least in British practice, did not appear until the BT10 bogies used under the Mark 3 stock. The Commonwealth bogies were the first to have hydraulic dampers, but only in the vertical axis, to compensate for the lack of inherent damping in the coil springs. (Leaf springs have built in frictional damping.) 

 

The hydraulic dampers fitted to modern bogies have no springs and are there simply to resist movement. The bogie adapts to curvature and restoration to the straight simply by the actions of the wheelsets.

 

Jim

[RRU]

Thank you Edwin and Jim. That is the first point dealt with.

 

Still on the track theme, whilst waiting at Malton for the SSE, I noticed these fishplates on the up line. This short piece of track which is only used by non stopping trains now, must have been built with these two bolt fishplates throughout.

I have never seen two bolt fishplates anywhere else. How common were they?

 

 

[RRU]

Here is a train using that track.

 

Peter

[jim.snowdon]

11 hours ago, RRU said:

I have never seen two bolt fishplates anywhere else. How common were they?

Not very. They get a mention in the 1943 (1st) edition of British Railway Track, but by the 1956 (2nd) edition mention of them is qualified by the line "Many lengths of track with short fishplates remain....", together with the comment that the expected maintenance benefits by bringing the joint sleepers closer together did not materialise, not least on account of the reduced rigidity of the 2-bolt plates compared to the standard 4-bolt type. The inference is that by some time before 1956 they had been abandoned for new work, which would suggest that the examples at Malton may have been in there for a very long time.

 

Jim

[RRU]

Thanks for the info Jim. There appears to have been some recent maintenance on them going by the spanner marks in the grease and grime. How often they are inspected I do not know.

 

There is no hinderence to the speed of trains because it may not look it from the photo but thr loco is accelerating hard at that point.

 

The strange thing is the sidings along side have four bolt fishplates.

 

Peter

 

 

[RRU]

The reason for my travels on the railway over the last two years is/was to film the SSE. The loco being used this year is 45699 Galatea.

Here are a few pic`s.

 

Three generations of motive power at York 15-8 -19

 

45699 Galatea,     37669  37706,     66431

 

Peter

 

[RRU]

Two more. First one leaving York, second one at Scarborough.

 

Peter

[roythebus]

When the prototype looks like the model...

[RRU]

Last year the locomotive used on most days was 35018 British India Line, seen here at York, Malton and Scarborough.

 

Peter

 

[jim.snowdon]

13 hours ago, RRU said:

Thanks for the info Jim. There appears to have been some recent maintenance on them going by the spanner marks in the grease and grime. How often they are inspected I do not know.

 

There is no hinderence to the speed of trains because it may not look it from the photo but thr loco is accelerating hard at that point.

 

The strange thing is the sidings along side have four bolt fishplates.

 

Peter

 

 

Without looking up the relevant track standard, I think the requirement is that they are greased at least twice a year - Spring and Summer to avoid them becoming locked up and preventing expansion.

 

Jim

[RRU]

22 minutes ago, jim.snowdon said:

Without looking up the relevant track standard, I think the requirement is that they are greased at least twice a year - Spring and Summer to avoid them becoming locked up and preventing expansion.

 

Jim

 One of the few places not to be prone to buckling in the recent hot weather?

 

Peter

 

[62613]

2 hours ago, roythebus said:

When the prototype looks like the model...

Soon as I saw it!

 

[RRU]

On the second to last and the next to last runs 45690 Leander was used.

 

[RRU]

On the last day 8f 48151 was used.

 

This is all leading up to two things on that last day that I am not sure about.

 

Peter

[RRU]

My first query is about this vehicle and why it was in the train.

 

When I asked one of the train staff he seemed a bit reluctant to tell me, but he did say it was to help the diesel loco or words to that effect.

I then asked the fireman and he said it was so they could have a brake. He then ran off and climbed on the engine.

 

Now, did he mean a break or a brake. I think the latter because they were eating their fish and chips whilst sat on the platform seat.

 

 

 

 

The diesel loco`s used that day were 37669 and 37706.

 

Peter