Prototype for everything corner.

[Davexoc]

10 hours ago, Titan said:

 

The last thing you want on a passenger train is the loco buffering up and then snapping the coupling tight when the coach brakes come on. Prior to the brakes being applied, the loco coupling will already be tight due to the springs in the buffers keeping it that way, so if the coach brakes come on first it keeps the coupling tight and there is no snatch. There will be no wheel flats either, as drivers are not in the habit of going straight into emergency application on a normal service stop, so the brakes on the coaches will only have had a gentle application before the loco brakes start to come on in proportion to that of the coaches.

 

But as the driver applies the brake, the first vehicle to react to the decaying brake pipe pressure is the loco, with the last being the rearmost vehicle. Therefore the weight transfer is forward and the coaches buffer up to the loco. To work the way you are saying to keep the couplings in tension, the first vehicle to brake has to be the rear one, the last one to see the drop in pressure....

[Titan]

1 hour ago, Davexoc said:

 

But as the driver applies the brake, the first vehicle to react to the decaying brake pipe pressure is the loco, with the last being the rearmost vehicle. Therefore the weight transfer is forward and the coaches buffer up to the loco. To work the way you are saying to keep the couplings in tension, the first vehicle to brake has to be the rear one, the last one to see the drop in pressure....

 

None of the above is true. It has been explained very clearly how it works, by people that have been trained on, and work the real life locomotives, and that includes me as I trained on them under BR. This means we are explaining exactly how it is, not opinion.   However what we can't do is understand it for you.

[37114]

15 hours ago, Michael Hodgson said:

If you want to run a brake van special, you need to have a supply of serviceable brake vans sitting around doing nothing else.

And Vac fitted ones as well. I did a Brake van ride once, 2 vans behind double headed class 37 on the GWSR. It was bumpy and there were about 15 of us on each veranda 

[leopardml2341]

10 hours ago, Titan said:

 

None of the above is true. It has been explained very clearly how it works, by people that have been trained on, and work the real life locomotives, and that includes me as I trained on them under BR. This means we are explaining exactly how it is, not opinion.   However what we can't do is understand it for you.

Perhaps some mention of how 'distributors' function in an automatic air brake system may help as well?

 

I know a little of their principle I.e. that they respond (more quickly) to the drop in train brake pipe pressure and vent local reservoirs to reduce the brake application propagation delay, but not enough to offer a more detailed explanation in the context of this discussion. 

[Gibbo675]

2 hours ago, leopardml2341 said:

Perhaps some mention of how 'distributors' function in an automatic air brake system may help as well?

 

I know a little of their principle I.e. that they respond (more quickly) to the drop in train brake pipe pressure and vent local reservoirs to reduce the brake application propagation delay, but not enough to offer a more detailed explanation in the context of this discussion. 

Hi Andy,

 

Don't forget DA valves on vacuum systems.

 

https://www.railcar.co.uk/technology/brakes/?page=direct-admission-valve

 

Gibbo.

[caradoc]

18 hours ago, rab said:

Having done a brake van run on a preserved railway (25 mph max)

I don't think I'd fancy doing one in the mainline, running at the speeds needed to keep out of the way of service trains.

 

Agree absolutely, a brake van ride on the Epping/Ongar Railway in a Shark gave me a whole new appreciation of, and sympathy for, Goods Guards !

[LMS2968]

14 minutes ago, caradoc said:

 

Agree absolutely, a brake van ride on the Epping/Ongar Railway in a Shark gave me a whole new appreciation of, and sympathy for, Goods Guards !

To be honest, it was just part of the job. Unless it was an exceptionally rough van, we didn't usually think about it.

[hmrspaul]

54 minutes ago, caradoc said:

 

Agree absolutely, a brake van ride on the Epping/Ongar Railway in a Shark gave me a whole new appreciation of, and sympathy for, Goods Guards !

I've done the same at Scunthorpe. But, a BR Shark has only a 9ft wheelbase and were used in a different way to the standard revenue brake van with their 16ft wheelbase. Not good I'm sure, but certainly better to a Shark. I don't know if Sharks were ridden in to a job, or only when in use at a job when movement would be very slow - probably slower than on heritage railways. 

 

Paul

[bude_branch]

On 03/09/2021 at 08:30, rodent279 said:

You don't see brakevan tours anymore these days.

When was the last run, and is there any reason why it couldn't be done now, on the mainline (apart from the lack of brake vans)?

 

M7 30053 worked a series of trips from Salisbury around the Laverstock Loop on 28th June 1992 using a pair of Queen Mary bogie brake vans.

 

I'm not sure what happened here, I meant to include a link to Terry Foulger's picture but it seems to have posted the image instead.

Copyright: Terry Foulger / Justin Foulger

https://flickr.com/photos/justinfoulger/49850934776/

Edited September 6, 2021 by bude_branch

[john new]

1 minute ago, bude_branch said:

 

M7 30053 worked a series of trips from Salisbury around the Laverstock Loop in 1992 using a pair of Queen Mary bogie brake vans.

 

920611_salisbury_m7-30053_brk-van-ride | Chris Nevard | Flickr

 

 

Rode them, good trip.

 

[montyburns56]

I don't know if an A3 shunting it's own train was that usual, but I'm sure I'll soon find out.....

 

60110 'Robert The Devil' at Leeds Central 1957 by Geoff Dowling

 

 

[Wickham Green too]

With the main train having arrived from 'Arrogate facing the wrong direction ( into the buffers ) it's logical to add the Leeds portion and change of loco in one move.

[john new]

I occasionally spotted at Leeds Central in that era and remember the Q of Scots. Nothing about the various stock manoeuvres has screamed odd at me down the years so I guess the outgoing engine did do the move. Using a shunter/pilot wold have.

 

[david.hill64]

21 hours ago, leopardml2341 said:

Perhaps some mention of how 'distributors' function in an automatic air brake system may help as well?

 

I know a little of their principle I.e. that they respond (more quickly) to the drop in train brake pipe pressure and vent local reservoirs to reduce the brake application propagation delay, but not enough to offer a more detailed explanation in the context of this discussion. 

In a standard air brake system, a distributor is a device in every vehicle that uses a drop in the pressure of the train brake pipe to determine how much air is fed to the brake cylinders from the vehicle's air brake reservoir. I would not use the term 'vent' in association with the local reservoir. The air pressure in the brake cylinders is proportional to the drop in brake pipe pressure over the normal operating range.

 

Note that there is some hysteresis in the system: things take time to react. When doing brake trials with new brake pads on HST's we found that although the brake cylinder pressures for full service and emergency applications should be the same; in practice cylinder pressures were always higher for the full service brake application. This was attributed to the hysteresis effect, with the distributor acting more quickly with the faster reduction in brake pipe pressure under an emergency application. (In normal service applications the system is slugged to protect the train against longitudinal dynamic effects. The slugging is different for passenger and goods, hence the goods/passenger changeover control). Although emergency brake applications on normal air braked trains didn't specify a higher brake force, it did specify a faster application.

 

The advantage that a distributor has over the older 'triple valve' is that is allows proportional release, which a triple valve doesn't but otherwise the principle is the same.

 

Some trains - eg HST- had a control signal that operated the brake controller at both ends of the train. This was done to reduce the brake signal propagation time, ie get the brakes applied on all vehicles as quickly as possible.

 

When you need fast application times - suburban multiple units for example - the control signal is electric to every vehicle. Moreover, in an attempt to reduce SPADs that had been attributed to deficiencies in the brake design of 3-step controlled disc braked units, the emergency brake rate was increased from 9%g to 12%g for those vehicles whose bogie designs could accept the higher forces,

[talisman56]

On 03/09/2021 at 10:59, Wickham Green too said:

Any trip to Horwich ( or elsewhere ) would have been one way at that date ! .............. oh - by the way, rab, it's an EMU !

Looks like that unit is ready for its last journey - open doors on the first vehicle, and the last one is the wrong way round for normal service...

[Wickham Green too]

....... not to mention the lack of glass in several windows.

 

According to Ashley Butlin, the last withdrawals were November 1980 and subsequent 1981 & 1982 disposals were to Mayer Newman at Snailwell ( motor coaches & driving trailers ) and Booths in Rotherham ( intermediate trailers - perhaps these had no asbestos ? ) - so I guess the shunter is separating the types.

[montyburns56]

Hindley 1986 by Alan Hart

 

 

Lostock Junction 1986

 

 

[montyburns56]

Crewe 1984

 

 

[melmerby]

Street running in Great Yarmouth:

[montyburns56]

Achnasheen

 

 

[rab]

1 hour ago, montyburns56 said:

Achnasheen

 

 

That could also be an entry for the

 "When the real thing looks like a model" thread

[SHMD]

1 hour ago, rab said:

That could also be an entry for the

 "When the real thing looks like a model" thread

 

Nah! The windows on the 25 look wrong...

 

 

Kev.

[keefer]

And the headlights aren't:

1) lit at all

2) (if they were lit) piercingly bright blue-white LEDs that would light the track all the way to Kyle/end of the baseboard

[60B]

5 hours ago, montyburns56 said:

Achnasheen

 

 

A 24/1 AND 27 (which in itself is a bit of a rare bird here) seem overkill here (though theres probably a good reason for it. The other thing that stands out is that the end  is punctuated by an open wagon of some variety. Incredibly little passenger accommodation even for the Kyle line.

[rodent279]

7 hours ago, 60B said:

A 24/1 AND 27 (which in itself is a bit of a rare bird here) seem overkill here (though theres probably a good reason for it. The other thing that stands out is that the end  is punctuated by an open wagon of some variety. Incredibly little passenger accommodation even for the Kyle line.

And seven covered vans stored in a siding seems overkill for such a small station.