LMR Buffering Arrangement as depicted by Hornby

[What About The Bee]

In another thread, some chat revolved around the LMR buffering arrangement depicted by Hornby. 

Hornby have a single leaf spring, with two rods leading diagonally to a coupling location. In that other thread, we discovered that this arrangement is not the Henry Booth patent of 1836, adopted by the LMR and other influential railways, as the Booth patent comprises 4 leaf springs. The buffering arrangement depicted by Hornby must therefore predate that 1836 patent.

I have found the appropriate reference. Once again, Nicholas Wood, Practical Treatise... , 1838. Plate VI

In the lower left hand corner, you may observe an undercarriage with a singular leaf spring. I offer the snip from that plate here, to be sure of your understanding 

The description of that plate can be found in the text. It specifically states that the arrangement is used on the LMR.

Plate VI, Explained

There are two items which jumped off the page. Firstly, what Hornby calls fine scale chains, Nicholas Wood refers to them as "drag chains"! Secondly, the darts or arrows show the direction of travel of LMR carriages! They are not to be run in random orientation, rather, the concave portion of the leaf spring must face forwards! Today I learned...

To further save my readers the exercise of pouring through pages of antiquated text, of matching letter references between text and plate that are hundreds of pages apart. Moreover, to show the full mechanical arrangement instead of forcing the reader to mentally manipulate images to realize the mechanism. Therefore, I have colorized the images and re-arranged the illustration to show the mechanism under two circumstances. Acceleration, that is, as the train leaves the station. Deceleration, that is, as the train arrives at the station.

Acceleration

The train is leaving the station from stopped.

Drag Chain, orange, couples the two carriages. Darts, pink, indicate direction of travel. As the carriage on the left pulls away, the carriage on the right resists the pull. The ends of the leaf spring, blue, on the left carriage are pulled by rods, yellow, connected to a center rod, green, which couples to the dra g chain, orange. This means the ends of the leaf spring, blue, are pulled away from the direction of travel. In the trailing carriage, the drag chain, orange, is connected to a center rod, yellow, which applies force to the center of the leaf spring, blue. This means that the center of the leaf spring, blue, is pulled in the direction of travel.

Deceleration 

The train is arriving at the station and coming to a stop.

The drag chain no longer has any affect. I will begin with the description of the trailing carriage, as this is fairly easy to see. The buffers have a long sliding rod, navy blue, which are coupled to the ends of the leaf spring, blue. The carriage momentum pushes against the ends of the leaf spring, blue, leading to a controlled stop (well, not so much). The leading carriage is also involved in this process, albeit with a much more complicated arrangement. The buffers lead to a short rod, navy blue. These are connected to diagonal push rods, yellow. The diagonal push rods are connected to pivoting reversing rods, red. The pivoting reversing rods are connected to short pulling rods, green. These in turn are connected to the singular leaf spring, blue. Therefore, a push on the trailing buffers on the leading carriage results in a pull against the ends of the leaf spring.

In acceleration and deceleration, the leaf spring in each carriage is involved. Not explained are the series of end stops required to make the middle and ends of the leaf springs react under different load directions.

Now the sharp eye will detect a gear on the carriage, which is not involved in the buffering. At last, the method of carriage braking is within my grasp. That gear provides the mechanical advantage for the guard to apply the brake.

Bee

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@Bee

An informative dissertation, thank you. No wonder there were complaints about uncomfortable journeys on the LMR, and not just because of the rough ride. I made a trip on an"heritage" railway where the screwlink coupling was not wound up between 2 carriages, leaving a gap between the buffers. The pronounced fore and aft motion of the carriage during the trip was most uncomfortable. Travelling in the LMR carriages must have been even worse, unless the tail carrriage was braked sufficiently to keep all couplings in tension at all times. Keep all this fascination coming!

[What About The Bee]

Hi Threelink

When examining these configurations, I think it important to consider context.

Before this buffering arrangement, there were coiled springs in leather bags and before that wood bashing on wood. We also know that this buffering arrangement was superceded by Booth's patent of 1836. So it is a snapshot in time.

This arrangement certainly was an improvement over nothing at all. Consider the carriages simply crashing into the one ahead. All the energy, dissipated at once, resulting in high deceleration forces. The coiled spring arrangement was little better. Force is linearly proportional to compression for coiled springs. If made stiff enough (k of the spring high), then a lightly loaded carriage will feel the same as crashing without springs. The carriage crashes into a stiff spring and there is no compliance. If the spring is made more compliant to soften a lightly loaded carriage (k of the spring low), then a heavily loaded carriage will bottom out the coiled spring, end of travel, resulting in yet another crash. Was the coiled spring better than nothing? Yes, but still insufficient.

The buffering arrangement presented here was better. Greater travel of the spring results in more energy dissipation before crash. From an engineering standpoint, the rearward facing buffers present significant bending dilemmas in the mechanism. The diagonal rods connected to the reversing rods have forces applied in angles away from the axial sense. That results in bending moments. Trying to use one spring for multiple functions is an admirable engineering goal, yet a spring must have something to react against. I specifically did not discuss the reaction force arrangement before. The hard stops of the spring travel, when the ends and middle are moving, isn't really workable over the variables we see here. But was this arrangement better than before? Oh yes it was.

The continuum of development pressed onwards, with Booth distributing the multiple functions to individual springs in 1836. Was this better? Oh yes, it was.

Context is important. The LMR was a grand laboratory. Rails, sleepers, locomotives, carriage design, and on and on; it was all on! Buffering included.

I've now read a few reports, such as yours, of the rough rides on heritage lines. Permit me to express my jealousy. I'd really like to experience that rough ride but alas, wrong side of the Atlantic. The lads running the heritage line are doing the best they can, with antiquated, worn out equipment, on irregular rail. You still got the ride and likely had fun! Still jealous!

Bee

[What About The Bee]

The LMR brake mechanism is presented. As usual, Nicholas Wood, Practical Treatise... 1838 

At the top of the image, we have Jupiter, LMR #14, manufactured by Robert Stephenson & Co in 1831. Jupiter was a 'Planet-Type' locomotive, in 0-4-0 configuration. Behind Jupiter, there is a third generation tender. Behind the third generation tender, there is 1st class carriage Traveler, with guard. Of note, Traveler is definitely in Hornby R30232 and should be in Hornby R30090 (time will tell).  

In the middle of this image, presented is the original depiction from Plate 6, showing the undercarriage used on the LMR.  

On the bottom, I have annotated the brake mechanism. The forward orientation of the carriage is the same. Forward is to the left hand side the image. The guard's right hand will apply the brakes, as the handle(1) is to the right of the guard. To apply the brakes, the guard will rotate the handle (1) clockwise, which causes the rotation of the gear (1) clockwise. This causes the gear (2) to rotate anti-clockwise. Gear (2) drives a double pinion. Rotating gear (2) anti-clockwise causes the red rod (3) to move towards the rear of the carriage, as shown by the yellow arrow. Simultaneously, gear (2), via the double pinion, causes red rod (4) to move towards the front of the carriage, as shown by the yellow arrow. The motion of rod (3) causes the sub-axle(5), green, to rotate, as shown by the pink arrow. A reversing rod on sub-axle (5) causes the brake shoe to be pressed onto the drum of the forward wheel, small yellow arrow. Similarly, the motion of rod (4) causes the sub-axle (6), green, to rotate, as shown by the pink arrow. A reversing rod on the sub-axle (6) causes brake show to be pressed onto drum of rear wheel, small yellow arrow.

To disengage the brake, lever at (1) is rotated anti-clockwise. This will cause the break shoes to be pulled away from the drum of the wheels, in a reversal of the above description.

As (a) the brake mechanism is actuated via the handle shown (b) there only is one handle depicted in the Wood plate, and © the position of that singular handle is on the front of the carriage; therefore the guard should be seated facing forward.  Most of the carriages depicted, with a guard, have that guard facing forward.  Ackermann, Freeling, Colyer, Crane and Sandars only show forward seated guards. Ackermann, Crane and Freeling go so far as show that there is no rearward facing guard station, even with the rear of the 1st class carriages quite visible. It simply isn't there. Admittedly, Crane and Freeling are derivative images.

Yet there is one image which must be examined.  James Scott Walker, An Accurate Account of the Liverpool and Manchester Railway ... 1832, has a plate which includes a rake of 1st class carriages in the Olive Mount Cutting. A spectacular image, giving a sense of the depth of the cutting.

Walker Plate

The first carriage in consist has a forward facing guard. The last carriage in consist has a rearward facing guard. Further, the handle (1) appears to be visible for inspection, mounted atop a long rod! The rod appears mounted to the outside face of the carriage. This is consistent with the position shown by Wood.

The gears (1) and (2), must therefore be in the undercarriage. I think you can see the gears in the undercarriage on the full Walker plate, but this is not certain. What ever that is is in the right spot for the gears and, to me, looks like gears, but your mileage may vary.

If we accept Wood and Ackermann, and we should, then there is no rearward facing guard station.  Therefore this last carriage is being pulled from the wrong end, facing the wrong way for travel. The alternative is that there were two guard stations, albeit not shown by any period illustration I can find.

Bee

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@Bee

Another learned exposition, many thanks. Yes, the heritage ride was fun notwithstanding the discomfort - no complaints from me. One wonders whether the forward facing position of the LMR guard was to enable hand signals to be given by the loco crew to instruct braking by the guard. I cannot see that a rearward facing guard would be of much use, except to look out for breakaways. The ingenuity of the pioneer railway engineers in seeking to address the technical difficulties of coupling, buffing and braking (amongst other things) is really quite remarkable.

[What About The Bee]

One wonders whether the forward facing position of the LMR guard was to enable hand signals to be given by the loco crew to instruct braking by the guard.

 

 

That Walker plate is most instructive. Common sense tells us that the braking force should be applied at the last carriage in consist. Yet how is that guard to communicate with the engineer and fireman up front? Interestingly, many of the images include a guard riding in the first carriage in consist. Hand signals indeed!

I have looked at that Walker plate for a very long time. Never noticed the handle before, as it blends into the rock face behind. The slog through Wood's excellent drawing provided the spark. I examined each drawing in turn to look for that handle, and there it was!

And now my conundrum. Do I add a tiny wire to my Hornby 1st class carriages? This to represent the brake handle and rod running down the face. A tiny gear?

Hornby have suffered under an anachronism. Carriages today are double ended and have been for over a century. It is reasonable to assume then, that carriages on the LMR were double ended. Clearly, they are not. All of the evidence supports a singular guard station. Yet Hornby have placed two guard stations on the roof. Its understandable and does afford a sense of symmetry to the design. Hornby gets a bye on this from me.

Bee

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If the front and rear guards (and any others) were all forward facing, hand signals instructing braking could be passed from loco crew to the front guard and by him to the rear guard(s), rather like the hand signalling method employed on the Talyllyn slate train where gravity is the sole motive power and brakesmen sit on the wagons, receiving hand signalled instructions from the leading brakesman. The loco steam whistle appears not to have been invented until 1833 (George Stephenson's "steam trumpet"on the Leicester and Swannington railway) so in the absence of some early version of the Harrison cord, hand signalling would seem to have been the only means of communication in the early days of the LMR. If it were so, all guards must have faced forward. Is the guard in the Walker plate a forward facing front guard turning to the rear to pass back a hand signal - perhaps to release the rear brakes, he having released his own using the roof top handle? I am not familiar with the Walker plate so may be talking nonsense.

I am sure that in the interests of historical accuracy you will want to add a representation of the brake handle and rod and remove all duplicate, rear facing, guards seats.

[What About The Bee]

Hi ThreeLink

I've just now went through Walker, to see if a description of the guards or the plate would be forthcoming. Alas, no further information is provided.

I do have two tidbits. The tightest radius of curvature on the LMR, per Walker, was a radius of 15 miles. Secondly, should you wish to book a passage for your private, four wheeled carriage, the price was 20 shillings (Forgive me if I haven't the slightest idea what value this represented in 1832.)

The link to the entire plate was given, but in the interests of ease of discussion, I present it here

It very much appears that the guards are communicating by hand signals, just as you suggest. You did suggest that they should both be seated forward for convenience of communication. I agree. Yet, they are not! This lends further support to the inverted direction of that last carriage. Why would that guard sit wrong way around if he could easily sit facing forward and thus communicate more readily?

Bee

[What About The Bee]

I found an online calculator which purports to convert monetary amounts into values for the year 2000.

http://www.concertina.com/calculator/

Upon entering 20 shillings for 1832, I was informed that this is equivalent to £605.81 in the year 2000.

An equivalent fare may be Amtrak, which offers to transport your automobile from Washington DC to Orlando, Florida for £167.92 ($208). This is a distance 1363 km (847 miles).

[threelink]

@Bee. I missed the link to the full plate - sorry. Yes, the plate raises more questions than it answers, especially as to the orientation of the carriages - unless the train is being shunted backwards, towards the viewer? I do not know what was the track layout in Olive Mount cutting at the period and whether such a shunting movement would make sense. Even if it did, it would not explain why the far guard appears to be "wrong way round" (unless the purpose of the shunt was to turn the nearest carriage on a turntable). I doubt that the conundrum will ever be solved. Rail travel with a private carriage certainly was expensive.

[What About The Bee]

You asked about shunting and turntables in the Olive Mount Cutting.  Wood "Practical Treatise..", 1838 provides extraordinary information about LMR points and railway turntables in general.  

A detailed track plan of the LMR has eluded me. We do know, in broad stroke, much of that plan due to early Ordnance Surveys. Yet in detail, there is a great unknown. While it is possible that turntables and or points could be in the Olive Mount cutting, the answer simply is, I do not know.  

A fantastic resource is Fitzgerald "Liverpool Road Station, Manchester An historical and architectural survey" 1980. The entirety of the track plan at the eastern terminus is given. My count is 48 turntables in the terminal! That is no typographical error, forty eight turntables. I truly wish this type of resource was available for the remainder of the railway. I am hopeful that LMR corporate surveys and track plans were preserved and will someday be published.  

The Olive Mount cutting will likely not appear on my layout. Impressive an engineering feat as it was, it simply does not lend itself well to a model. The real cutting in 1832 was (up to) 70 feet deep and only 20 feet wide. Double track, single working. In OO, that's nearly a foot deep and only 3⅛" (80mm) wide. A wonderful view of the top of the cutting and no train spotting. Maybe it would be good for an on board camera. A derailment would be disastrous!!  

But for the period illustrators, the cutting was spectacular. The soaring majestic walls and the observer in the base of an extremely narrow canyon.  

Ackermann, as an experienced publisher, recognized the economic value of the LMR images. Multiple editions were published and variation among editions do exist. The image above appears in the first edition. While this edition illustrates a passenger consist of 1st class carriages, later editions show a 2nd class carriages.

With two guards present, we can observe what you theorized, and may I say, spot on. Both guards are seated forward. This would permit relatively easy communication. The guard in the rear would always have the guard in front in view. Likewise, the guard in front would have the engineer and fireman always in view. When the brakes were needed, the communication from the engineer to the guard in the rear would be relatively fast. A rearward facing rear guard could be day dreaming and completely miss his order.

While both the Ackermann and Walker prints of the cutting appear very early, they are not derivative images. It is hard to understand why Walker would illustrate that carriage backwards. But he did, showing us that view of the brake handle in elevation. Thank you, James Walker!

Bee