Design Your Own BLT

[PatB]

Didn't the North British have a gravity run-round branch terminus somewhere? I'm sure I read about such a thing but can't for the life of me remember the location. RM carried an article on it in the 70s or 80s.

[Nearholmer]

“The gradient in the tunnel from Canal Street to Scotland Street was 1 in 27, too steep for steam locomotives, and trains were rope-hauled up it by a stationary engine at the top of the gradient. Trains heading north (down the gradient) were controlled by brake trucks. A similar method of operation was used between Glasgow Queen Street and Cowlairs until 1908.“

 

Canal Street was a terminus in Edinburgh, serving lines to Granton/Leith.

Edited November 23, 2018 by Nearholmer

[Northroader]

Kevin, you're beginning to irritate me...

 

Over the weekend there are supposed to be some shelves going up in my room, the deepest of which is going to be over 18ins wide and the length will be around 5ft. Now, these shelves are needed for storage, and I was quite convinced that I wouldn't be able to fit a decent 4mm Standard Gauge layout on one and that I had quite enough 009 to content me for now. Then I read this. Now I find myself wanting a home for my (vaguely Welsh-based) BR Western Region stock.

 

And your plans may just be what would provide that.

On the other hand, there’s plenty of room on them shelves for an O layout. You might as well do it now, as wait til you’re old and doddery. Don’t fight the inevitability of it all.

Didn't the North British have a gravity run-round branch terminus somewhere? I'm sure I read about such a thing but can't for the life of me remember the location. RM carried an article on it in the 70s or 80s.

Eyemouth, dear boy. Railway Modeller March 1975. Edited November 23, 2018 by Northroader

[clachnaharry]

Loch Tay and Banff

 

(and Peterhead I think?)

 

The gravity shunt was performed at Killin rather than Loch Tay itself, which had a run round loop. The passenger service was cut back to Killin in 1939, although the line remained open for the mile or so to Loch Tay just for access to the engine shed until final closure in 1965.

 

Peterhead had no loop and was gravity shunted.

[Harlequin]

Gravity shunting is academically interesting but is it possible to model it realistically?

 

How would the carriage be braked while the loco was uncoupled? Would the carriage accelerate too fast because of momentum scale problems? How would the carriage avoid clattering into the buffers?

 

I can imagine installing a DCC controlled progressive braking system in a carriage to allow for all of the above but has that ever been done?

[Stevebr]

On the other hand, there’s plenty of room on them shelves for an O layout. You might as well do it now, as wait til you’re old and doddery. Don’t fight the inevitability of it all.

Eyemouth, dear boy. Railway Modeller March 1975.

RM article also had plans of the station building.

[scottystitch]

Gravity shunting is academically interesting but is it possible to model it realistically?

 

How would the carriage be braked while the loco was uncoupled? Would the carriage accelerate too fast because of momentum scale problems? How would the carriage avoid clattering into the buffers?

 

I can imagine installing a DCC controlled progressive braking system in a carriage to allow for all of the above but has that ever been done?

I saw this modelled and carried out at Model Rail Scotland 2 or 3 years ago, on an OO layout. I have a video somewhere that i took on my phone. Sorry I don't know the name of the layout off hand.

 

The coach had a black beetle(?) motor/bogie in it, so when the coach was backed out of the platform and the locomotive detached and despatched to a siding, the coach was able to motor back down to the buffers under its own power, appearing to be doing so by gravity. I'm guessing it was DCC.

[scottystitch]

I saw this modelled and carried out at Model Rail Scotland 2 or 3 years ago, on an OO layout. I have a video somewhere that i took on my phone. Sorry I don't know the name of the layout off hand.

 

The coach had a black beetle(?) motor/bogie in it, so when the coach was backed out of the platform and the locomotive detached and despatched to a siding, the coach was able to motor back down to the buffers under its own power, appearing to be doing so by gravity. I'm guessing it was DCC.

Found it!!!

 

Not my video, but this is the one. Inverboyndie. The sequence is different from what I remember and described. Apologies.

 

Edited November 23, 2018 by scottystitch

[PatB]

On the other hand, there’s plenty of room on them shelves for an O layout. You might as well do it now, as wait til you’re old and doddery. Don’t fight the inevitability of it all.

Eyemouth, dear boy. Railway Modeller March 1975.

 

Thanks,. Yes, that's the one I was thinking of.

 

As for modelling gravity shunting, I gave serious thought to how it might be achieved in 7mm on a light railway micro I was contemplating, O gauge stock having the necessary heft to have a fighting chaance of moving realistically. I was thinking in terms of holding the coach with a piece of piano wire rising vertically through the baseboard and bearing on an axle. Being under the coach when deployed it wouldn't be too noticeable. For stopping in the platform without hitting the buffer stops, the best I could think of was very careful adjustment of gradients and the use of a dedicated coach (easy enough on a micro with only one coach in use) of known rolling characteristics. Another option might be a slightly tight checkrail to brake the leading axle unobtrusively. Depending on how fussy you are it might be necessary to think up a prototypical excuse for the checkrail to be there.

[The Johnster]

Gravity shunting was carried out with passenger (but not passenger carrying) stock to release the locomotive from the down side bay platform at Wellington (Shropshire), between Wolverhampton and Shrewsbury.   The train would arrive in the bay platform (from Buildwas and the Much Wenlock route), and, once the passengers had detrained and any parcels had been unloaded, would set back into a kickback siding on a gradient.  

 

The Guard would then apply the handbrake in the brake coach, and, with the loco uncoupled, release the vacuum brakes on the whole train; you do this by pulling the brake release cord under the solebar, the position of which is marked by a white star, and which admits air at atmospheric pressure to the vacuum side of the piston in the cylinder, releasing the brake until the vacuum is re-created.  The loco would then exit this siding and stand clear on another road.  When the road was set and all was ready, the guard would release the handbrake and the coaches would roll back in to the bay platform, to be stopped by the Guard with the handbrake.  The loco would then back down on to the train, and couple on, the vacuum brake being re-connected at this point.  A continuous brake test would be done and the train would be ready to be boarded by passengers and depart.

 

Doing this is model form is a challenge, but not impossible.  The simplest method, though not the cheapest, would probably be to motorise the brake coach with DCC control.

Edited November 24, 2018 by The Johnster

[OhOh]

Very interesting thread to a novice such as myself who, up till now, thought that a conventional runaround loop was an essential element of every steam era BLT

 

On a small layout, I'm wondering if some sort of set-up with moveable or electro magnets under the track could be used to control gravity shunting?

[The Johnster]

Hmm.  Magnets that powerful might have a deleterious effect on your motors; I don't like the sound of it, and what they'd do to DCC chips is anyone's guess.  

 

The ability to run around the stock is a usual feature of any steam era BLT that was not operated by some form of push pull passenger service and where there was no permission for propelling freight, but it doesn't have to be a run around loop as such, as we've seen.  In urban locations especially, space was usually at a premium and expensive to purchase; track layouts often reflect this, as do situations on hillsides where a minimum of excavation will be indulged in.  

[brianusa]

It's surprising no one has mentioned probably the most famous example of all, Yelverton, on the Princetown branch, where the loco left the  carriage on the sloping branch line. Uncoupled, then advanced to the station and reversed into the turntable siding before the Guard rolled the carriage into the platform.  When signaled, backed onto the carriage, ready for the next Princetown service.

 

Brian.

[Siberian Snooper]

Gravity shunting was carried out with passenger (but not passenger carrying) stock to release the locomotive from the down side bay platform at Wellington (Shropshire), between Wolverhampton and Shrewsbury.   The train would arrive in the bay platform (from Buildwas and the Much Wenlock route), and, once the passengers had detrained and any parcels had been unloaded, would set back into a kickback siding on a gradient.  

 

The Guard would then apply the handbrake in the brake coach, and, with the loco uncoupled, release the vacuum brakes on the whole train; you do this by pulling the brake release cord under the solebar, the position of which is marked by a white star, and which admits air at atmospheric pressure to the vacuum side of the piston in the cylinder, releasing the brake until the vacuum is re-created.  The loco would then exit this siding and stand clear on another road.  When the road was set and all was ready, the guard would release the handbrake and the coaches would roll back in to the bay platform, to be stopped by the Guard with the handbrake.  The loco would then back down on to the train, and couple on, the vacuum brake being re-connected at this point.  A continuous brake test would be done and the train would be ready to be boarded by passengers and depart.

 

Doing this is model form is a challenge, but not impossible.  The simplest method, though not the cheapest, would probably be to motorise the brake coach with DCC control.

There was an exhibition layout of Wellington (Salop) on the circuit many years ago which had the gravity shunt, but I can't remember exactly how it was achieved. I think there may have been an article in one of magazines at the time.

[kevinlms]

There was an exhibition layout of Wellington (Salop) on the circuit many years ago which had the gravity shunt, but I can't remember exactly how it was achieved. I think there may have been an article in one of magazines at the time.

MRJ No. 64 & follow up info on workings in No. 65.

[stivesnick]

_{There was a layout at the Royston show a few weeks back, that had a siding on a gradient for gravity shunting on the passenger train - although the operators noted that the stock they had on the day was not free running enough for shunting. This layout also had a loop, which was often used to store wagons so not available for use in running round trains.}

 

_{I recall seeing another layout with the feature many years ago. The coaches were held in position by a very non-prototypical bar that rose up between the tracks to stop the coaches from  moving.}

 

_Regards

 

_Nick

[clachnaharry]

Paul Karau's book on the Watlington branch states that rope shunting was used to run round goods trains which were longer than the very short (8 wagon length) run round loop.

 

The loco uncoupled and drew forward into the headshunt, the point was set back to the platform road and the loco reversed along the loop as far as possible. A rope was attached to one of the wagons on the platform road, and the train was pulled clear of the loop entrance point, allowing the loco to reach the other end of train.

[jcm@gwr]

Hmm.  Magnets that powerful might have a deleterious effect on your motors; I don't like the sound of it, and what they'd do to DCC chips is anyone's guess.  

 

Ahh, but the magnet can be on a move-able, swivel-able mount, that is

only swung into position once the loco is out of range!

[Nearholmer]

I didn't expect to provoke such a discussion of gravity-runarounds!

 

New up, number nine is the turntable-release version of the foregoing, which was very popular up to perhaps the 1870s, and remained at a good few 'fossilised' termini where locos never outgrew the turntable.

 

I've also added a siding on the 'wrong' side of the main-line, to show that it introduces complexity in the form of trapping and facing-point locking. On the main goods yard side, I've added a head-shunt, to allow shunting to continue while passenger trains come and go.

Edited November 26, 2018 by Nearholmer

[Zomboid]

Turntable release is also still popular with narrow gauge railways, such as the Bure Valley and Ravenglass & Eskdale.

[Joseph_Pestell]

Going back to the gravity shunting, Maiden Newton was a notable example (but that, like Wellington, is at the junction end of the branch rather than the terminus).

 

That has certainly been modelled. I think that the loose carriages were held in the inclined siding by a rod pushed up between the rails. And then a bit of gauge narrowing of the track in the bay platform was used to provide a brake.

[Jongudmund]

There has been a great deal of discussion of Branch Line Termini on RMWeb, with examples being cited from railways all over the place, but people still getting a bit foxed on occasions by the 'whys and wherefores', so I thought it might be interesting to discuss a DIY approach, which might lead to feasible-freelancing.

 

So, sticking with Britain, and the 'classic' era from c1890-1960, and starting with a really, really simple BLT, with a view to gradually building-up complexity as matter progress......

 

Three termini of a very simple kind, suited to places with very limited traffic:

 

The first is simply a single track, ending at a platform! It can clearly only be worked by something that can be driven from each end, an auto-train/motor-train, or some sort of railcar, because there is no facility to 'run round'. No signals, because the section from the passing-place on the right is worked "one engine in steam", probably using a train-staff.

 

Is it worth modelling? Well, maybe if you like weird and wonderful railcars. Is it prototypical? Certainly the LT branch from Acton Town, known as The Acton Shuttle, was pretty much like this, and there were probably others in the classic period.

 

 

This is the Cardiff Bay station in the current era. One-car trains zipping down from Queen Street and back along a viaduct with a road each side. The 'station' is a platform and a derelict building. 

[Northroader]

It’s just the proportions of the turntable as a loco release that go against it. Bembridge IoW was small and neat, to the extent that it needed enlarging when the O2s were introduced. You really need to make it big enough to take a small tender engine, then when you draw out a circle this size, you notice it’s beginning to fill the width of the baseboard, a lot of “dead space” on a small station. Possibly this was what Beal had in mind when he drew a sector table in his book “Modelling the old time Railways” It looked just like a turntable, but pivoted at the one end, and just traversed the width of the tracks. One line I made tried this, but then I found the snags. Having the pivot at one end meant it wasn’t balanced, and very stiff to turn without rollers at the other end. The main problem which it shared with a turntable was when you did shunting, you soon found out that the table needed to be lined up with every move from the other end, or you’d soon get something down in the pit. If you had a passenger train arriving you would need to be sure the table was lined up, most likely the Board of Trade must have insisted that the table was approached by a point merging the runround before the table. (Langholm NBR, Alston NER, Hornsea NER are examples.) This does away with the space saving feature on a model layout.

[Fleetfoot Mike]

This is the second time I have mentioned this today (in a thread on Fairford) so sorry for the repetition.

The station was not really planned to be a BLT; it was just built as through station and happened to be where the money ran out, so the rest of the line never got built.

 

I'm reminded of Longville on the Wenlock branch, which after it was shut for passenger traffic, also become the de facto terminus. In a reversal of the above, it was essentially a loop with headshunts top and tail, and the main line then continued to the now-disused single platform and stopped. 

[stivesnick]

_{There was a layout at the Royston show a few weeks back, that had a siding on a gradient for gravity shunting on the passenger train - although the operators noted that the stock they had on the day was not free running enough for shunting. This layout also had a loop, which was often used to store wagons so not available for use in running round trains.}

 

_{I recall seeing another layout with the feature many years ago. The coaches were held in position by a very non-prototypical bar that rose up between the tracks to stop the coaches from  moving.}

 

_Regards

 

_Nick

 

 

The layout at the Royston Show was called Porlock by Kevin Grace

 

Regards

 

Nick