Jump to content

LMR Livestock Wagon Project


Recommended Posts

With the very attractive price on flatbed wagons, I ordered a few sets about 8 business days ago. They have arrived and I must say, the packing job was superlative. They were bundled up in a cocoon of bubble wrap

forum_image_657107cbaf824.thumb.png.d46b8a3c6991445ac486cb8ea1b05df8.png

Here is a flatbed wagon apart. Since there are no instructions or exploded parts diagram, I was forced to muddle through. Removing the two screws is easy, but the floor would not come out. There are four locking tabs which engage the chassis. Slide a razor blade horizontally betwixt the chassis and floor and gently prise each corner up, releasing the locking tab.

forum_image_657107d5e9d17.thumb.png.a3ff480425f0467f344607741da5ff89.png

The floor was swiftly reverse engineered into FreeCAD, so that the new design will meet the existing chassis.

forum_image_657107dba35a0.png.88ebe297dec8bf8293847138cc65b766.png

I will start with the Livestock Wagon, used for pig and cattle. The animals are retained on the wagon with stake sides or fence sections.

forum_image_657107dd92bb0.thumb.png.9f331dc772872078ef59cdbca23bfaa7.png

With the four stake sides sketched, I encountered the tricky bit. I want them to work as they would on a real wagon. Wagons use bolsters, a stub vertical member. Straps are used to receive the post of the stakes.

forum_image_657107e05760f.thumb.png.c90eb2534cf5f6b8fc00792726ce5cb9.png

After quite a bit of fiddling around, I finally realized that bent copper wire would act just as the straps on an actual bolster.

Here is the Livestock with two stake sides removed

forum_image_657107e5ea3ec.png.0f782e0b2ff913c31183807646fc8cb0.png

A close up of the bolster with the post in place

forum_image_657107e7eee89.png.eaa73c15590ee3d9d63a59e6be4f325e.png

And with the post removed.

forum_image_657107e9d74bc.png.dd1eb59b7858f5a19dcba3c15e08b69a.png

The bolsters are tabbed into the floor, so they will be on location to within 0.002". The wires around the post have a 0.2mm gap to the post, all around, or ~ 0.016" total tolerance. The posts should easily slide into the bolsters when assembled

forum_image_657107ebce366.png.8d270b0868a4878a7d29cbf70885e524.png

I will give this a bit more thought, possibly tweaking a detail or two. Fairly soon, I will have cattle and pig wagons rolling around the layout.

Bee

Link to comment
Share on other sites

Hi Simon

My bolsters are based on actual wooden wagons. I provided an image of an actual bolster in the original post.

Now the tricky bit is as follows. In real wagons, the horizontal members of the stake sides should be on the inside, placing them in compression against the vertical posts. On a real wagon, the bolsters are typically inboard of the vertical post, the post on the outside edge of the wagon. In this arrangement, the bolsters are under the horizontal members, conserving floor space.

The famous Ackermann prints of the LMR invert the members. They show the vertical posts inside the horizontal members. This means any attaching bolts will be in tension, which is a far weaker arrangement than is the above paragraph. The horizontal members would be on the outside edge of the wagon, the posts inboard of the horizontal members. Ackermann does not show any bolsters, but clearly any stake side wagon would have them.

This leaves me in the unfortunate position of placing the bolsters outboard of the posts, to properly conserve floor space, as would be the outcome of any arrangement.

As you may deduce, I am troubled by this inversion.

Bee

Link to comment
Share on other sites

Here is a wagon under construction by a master of the trade, Dave Engel. The orange arrow points to one of four bolsters visible in this image. The small yellow arrow points to where the post would sit. The bolster is inboard of the post. Find the other bolsters and you will understand the preferred arrangement.

forum_image_657272cead61c.thumb.png.12f3258c3dcd92e84161f4bb8584324d.png

But Bee, I hear you say, where are the straps on the bolster? The bolsters on this wagon are "ring type". These rings are trapped under the bolster strap, making the strap and each ring into two, two link chains. In use, the rings are brought horizontal and the post will thread down through the rings. This holds the post to the bolster.

Bee

Link to comment
Share on other sites

  • 2 weeks later...

When I self review a design, I must have a gap between when I design and when I review. It is always a good idea for me to let something simmer and think about what doesn't sit right. 

Here goes:

Dependent on breed, a cow has 4'6" shoulder height, roughly speaking. When I observe the cattle in the Ackermann long prints, the cattle shoulders are well above the top rail. First change, therefore, is to lower the top of the top rail to 45½ scale inches. That is ~9 scale inches below OO Scale cattle shoulders.

I would greatly appreciate a measurement of shoulder height from someone who has Hornby OO cattle. R7121

I noticed when looking at the wagons that Ackermann shows 4 rails on the slat sides.

forum_image_657e2345b03f8.thumb.png.ae79e58483b9f4e7f5a79d554b804695.png

The cattle leg may be seen standing on the floor, right by the pink arrow. The 4 rails above the floor are enumerated. Since my previous drawing only had 3 rails, this has been corrected.

Ackermann does not show how the slat sides are put together, leaving that detail up to the imagination. I imagine that there would be slender rods hammered over into rivet heads on either end. They would be staggered, to prevent a heavy slat side from acting like scissors when handled. As such, I added the fine detail of the rivets protruding. I will likely touch these with black permanent marker after painting, to emphasize the rivets.

The last change is a technical one. I intend these printed at Shapeways. There are minimum print dimensions for certain features. The bolsters needed a tweak, which bears mention.

So after these changes, the livestock wagon looks like this

forum_image_657e23485cfd1.png.f81bc732c7278f9d288decad044823f1.png

Scroll back up to see how it appears vs the earlier design. Slightly shorter, 4 rails on slat sides and rivets. The bolsters are different, but it simply isn't obvious.

Bee

Link to comment
Share on other sites

Hello Tony57

My limited research presented cattle (at shoulder height) ranging from 53" to 65", breed dependent. Fairly broad range. Yet a cow is a cow. An HO cow is likely close enough to pass muster for a OO cow.

I'm having enough difficulty with geometric shapes. I will be unlikely to design and print my own cattle. I will be left with commercially produced cattle, may as well be OO, may as well be Hornby.

I do have control over the height of the top rail of the slat sides. So given the shoulder height of the commercially produced cattle, I can adjust the design to match this appearance.

forum_image_657f1f1c9f949.thumb.png.03df907bd02b18801f85b7df0985a1b4.png

Still hopeful someone has Hornby cattle R7131 and can help me out. Failing that, one more request to Customer Care will be in order

Bee

Link to comment
Share on other sites

Hornby Customer Care has confirmed the height of the R7121 Cows at 1.3 cm (13 mm).

A quick bit of maths converts this to a cow 39" tall. For those who have actually encountered a cow or bull in real life, you will know this is a ridiculously short animal. Perhaps a calf, or maybe for forced perspective, but for a cattle load on the LMR, they are entirely too diminutive.

I have been looking at an eBay seller, who offers HO cows. Picking the two animals which indicate shoulder height (not tail, head, horns, etc), I see 16mm and 16.8 mm.

forum_image_6582fccf46e3b.thumb.png.1890840850d651288622418694489348.png

When inverse scaled back to prototype via HO, they are 54" and 58" tall at the shoulder, which is correct. When scaled at OO, they scale to 48" and 50½", a pinch on the short side.

Prepainted, direct from China. I think these will do. Launch the human figures directly into the bin.

Bee

Link to comment
Share on other sites

Hi Aussie Fred

"Perfect is the enemy of good" - Voltaire

The issue with using smaller cattle is that the slat sides of the livestock wagon are simply too tall.

In analysis of the cattle in the imagery, I determined that the slat side is between 80% to 84% of the height of the cattle.

Specifically, individual animals in the foreground permit observation of the hoof and shoulder. The slat side is immediately in front of that animal. By examining pixel addresses, I can determine a ratio.

Given the shoulder height of the cattle, I can determine the height of the rail.

"So far, so good" - Oliver Hardy

The problem of adjusting the rail heights on the slat sides is simply the available room. The bolsters take up a considerable portion, with four rails and three spaces taking up the remainder. I am caught in my own web!!

I have just been informed that https://www.wwscenics.com/product/oo-gauge-hand-sculpted-cows/ are 17mm from hoof to shoulder. Inverting the scale, I obtain 51", still 3" short of a nominal cow.

"Why are there no OO scaled cows?"

Bee


Link to comment
Share on other sites

Mikey,

Tiger is a reasonably good representation of a goods locomotive in the later LMR period.

The "coal wagons" it comes with are actually utility wagons used at the Rainhill Trials, in the construction of the railway and for maintenance of way ballast trains. The marketing dept at Hornby just named these little wagons the wrong thing. Coal was transported, but mostly in chaldrons. The collieries provided their own locomotives and rolling stock (chaldrons), paying a fee for use of the rails. There was a brief period during which the LMR offered to transport coal in intermodal wagons, but the collieries weren't having it.

Bee

Link to comment
Share on other sites

My procrastination is deliberate. It permits me more time to analyze without commitment. What cattle to select for this project has been a difficult problem. In thinking of the problem, I remembered the Rule of Three.

The Rule of Three

You will often encounter this phrase in old books. It is simply another name for a ratio applied to one value to obtain another.  

I will use the Rule of Three to find a solution for the cattle height, the height of the slat rail and etc.

I will begin with the Ackermann long aquatints. These show various consists. Passenger First, Passenger Second, Freight and Livestock. Each consist is shown with a locomotive, sitting on rail. The top of the rail, as it turns out, is a beautiful reference for analysis.

I clipped out a cattle wagon and a first class glass carriage and, using the foreground rail as a reference, aligned them side by side.

forum_image_658f6fee0b40c.thumb.png.785c00fadbf70073afb8d4632e74e1bf.png

The first rule of three is between arrows 1 and 2 (pink). The number of pixels in the image to the heights shown provide the ratio. The height of the Hornby Glass Carriage provides the known value, 34.9 mm, measured. This will provide us with the height of the slat over the top of the rail. 

72 pixels / 88 pixels × 34.9 mm = 28.55 mm

The height of the Hornby Chassis, 3 blue, above the rail is also known. It is 15.4 mm. The Hornby Chassis is used for all Hornby LMR rolling stock. Deducting the height of the chassis from the height of the slat side provides us with the height of the superstructure on the cattle wagon. 28.55 mm - 15.4 mm = 13.15 mm. [Result 1 = 13.15mm]

Yellow arrow 4 is the height of the super structure. The superstructure includes the floor on the Chassis and the Slat side.

The Rule of Three will provide the height of the slat side above the chassis compared to the height of the shoulder of the cattle above the chassis. Yellow 4 pixels divided by green 5 pixels. This provides us with the ratio of 0.82. That is, the height of the slat side is 82% the height of the cattle. But here, I cannot have an arbitrary bovine, I must use a commercial product. I will trial Langley F68A. Langley F68A shoulder height is 16mm, yellow 8.

forum_image_658f6ff070f92.png.cba8616062e8a13569c422013a294a47.png

We must be careful. There is a floor there. The cattle stand on the floor, not the chassis. The Hornby floor is 0.84mm, 7 orange. Rearranging terms in the Rule of Three by Algebra, I obtain (0.82 × height cattle) + thickness floor = 0.82 × 16 mm + 0.84 mm = 13.96 mm. [Result 2 = 13.96 mm]

At last I have a useful check. If I use Langley F68A, then the height of the slat side over the chassis(result 2) is 13.96 mm. If I use the Hornby Glass Carriage, then the height of the slat side over the chassis (result 1) is 13.15 mm. Those results are in reasonable agreement! Not precise, but close! 

Langley models are advertised as metal. Perhaps some judicious sanding on the hooves will shorten the cattle, shortening result 2, bringing it closer to result 1.  

As a final check, what is the shoulder height of the cattle above the rail if I use Langley F68A, green 6. This is arithmetic. Hornby Chassis + thickness Floor + height of cattle = 15.4 mm + 0.84 mm + 16 mm = 32.24 mm.  The pixel height of the glass carriage above rail divided by the pixel height of the shoulder of the cattle above rail is a ratio of 1.11. Multiply 32.24 mm by the ratio 1.11 yields 35.91 mm. Well glory be, that is the height of Hornby's glass carriage.

Langley F68A it shall be.

Bee


Link to comment
Share on other sites

It is not lost on me.  

I assumed that cattle on the LMR would be similar to today's cattle.

From the previous exercise, I found that the height of the slat side is 13.15 mm in OO, 39.45 inches (1.002 meter) on the prototype. 

Further, that the height of the cattle is 16 mm in OO, 48 inches (1.219 meter) on the prototype.

If we are to accept the consist aquatints by Ackermann, and I do, then the cattle depicted by Ackermann are fairly small.

So what could the cattle be? Farmers do not like horns. They can inflict painful injury, even accidental death. Horns are bred out, if possible. 

In a survey of common breeds of cattle in the British Isles, there are only a very few common breeds with horns. Naturally, there are always obscure breeds, like "Glamorgan", but this leads to a rabbit hole of exceptionalism. 

Common breeds with horns: "White Park" cows are, on average, 51 inches at the shoulder; bulls 57 inches. "English Longhorn" cows are 53 inches; bulls 59 inches. "Highland" cows 38 inches; bulls 44 inches. And that is exhaustive of common British cattle with horns.

The perspective of the wagon and cattle is odd. I note, with some amusement, that the bovine I selected in the foreground is among the shortest! The others are taller. Is that perspective? Or taller cattle?  Your guess is as good as mine.

The cattle in the Ackermann aquatints are probably White Park, given the wide distribution of herds, now even as far as Australia. Langley F68A is advertised as Highland.

Hahahaha! Have I just successfully argued myself out of yet another conclusion? 🤪

Bee

Link to comment
Share on other sites

BOLSTERS

There is another approach to bolsters which I had initially discarded. Holes in the floor, which are sized to barely fit the posts. The posts are held upright.

The first benefit is obvious. The appearance is much more like the Ackermann prints. The posts appear to come right out of the floor. 

The second benefit is more subtle: part reduction. It is always a good thing to reduce parts in an assembly, as this reduces cost and reduces build up of tolerance problems. From 35 parts to 5!

The drawback is insidious. The bases of the posts now protrude into the chassis, creating potential conflict with standard Hornby Era 1 chassis components. The wheels are critical, do not interfere with the motion.

To check, I added in the Hornby wheels and axles. I then thought of a way to add in the cattle artwork, scaling the cattle to the cattle wagon. It isn't perfect, just representative. 

forum_image_6595a468abd60.thumb.png.1ad5790e29c646913ac1383b0548792a.png

THE CONUNDRUM, EXPLAINED

At last I can see where the conundrum of the "small cattle problem" arises. When the slat sides of the Ackermann cattle wagon is made identical to the slat sides of my OO cattle wagon, I observe two things.

forum_image_6595a46bdf973.thumb.png.d8c1794bbeda6df7836d9be796dd92af.png

Firstly, the cattle are sized to the slat sides appropriately. Hurrah! The Rule of Three prevails.

Secondly, the Hornby wheels are entirely too large, raising the height of the chassis. If I am to keep to the overall height of the wagon, then both the cattle and slat sides must shrink! This is the nub of the conundrum, finally!!

Now to be careful, I do not blame Hornby for attention to the 1930s LMS reproductions of 1st class LMR carriages. I do not blame Hornby for re-using the 1st class chassis for all other wagons. Both make perfect business sense. Well done, actually. 

This just forces me to use smaller cattle to fit the imagery, an acceptable OO compromise. The conundrum of small cattle is resolved

Bee

Link to comment
Share on other sites

Shapeways has the models! 1 floor, 2 side slats and 2 end slats.

I selected tan fine detail plastic. This will be perfect for the floor color and perhaps not so perfect for the slat sides, as the depictions have either blue or green painted slat sides. I am very mindful that aquatints are representative of the publisher's whimsy, not necessarily representative of LMR colors.

My only concern now are the flimsy posts of those slat sides. I think they may break if I just glance in their general direction. I suspect they will eventually be required to be printed in metal. I selected plastic slat sides to check fit and function. Playing with that first engineering sample will put me on the same path as other manufacturers.

More to come in February, as the first samples arrive

Bee

Link to comment
Share on other sites

  • 3 weeks later...

I have just received my prints of the livestock wagon from Shapeways. This is the one most commonly used, given its appearance many times, across many aquatints, drawings, authors & etc. 

A quick recap. Convert a flatbed into a Livestock Wagon. A desired feature is that the slat sides would be removable. A test of how robust the slat sides are, questioning how fragile they might be.

Results

The floor snapped right onto the chassis. It is a near perfect fit. The integral clips to hold the ends onto the chassis functioned properly.

The slat sides function as designed. There is enough clearance to readily put the stakes into the sub-floor bolsters. 

forum_image_65b405ea55e98.thumb.png.d6a031a8e0c10f6c1a9d330e8d63b997.png

The slat sides are far more robust than expected. There will be no need for metal.

The rivets came out beautifully. They will be a breeze to paint.

Self Critique

There two bosses on the underside of the floor, each with a central bore to accept the retaining cross head screws. I sized the bore to the minor diameter of the thread. This was a mistake. The Shapeways 'tan fine detail plastic' is far too brittle. The screws did not self tap, as expected, rather, I heard brittle plastic fracturing. The bore will be larger next time. If you look slightly to the right of the top screw, a bit of broken plastic can be observed.

forum_image_65b405ef22eee.thumb.png.878d74ae7e2dede7dc81971d969d2303.png

The long slat sides are slightly warped. I did expect the parts to be flat. The warp isn't enough to deny the fit, but I can definitely feel resistance, taking up all the built in tolerance. I need to increase the fit tolerance, making it slightly more open.

Overall, I'm happy! I've learned a few things. Paint is next.

Bee

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
×
  • Create New...