CP Rail Aluminum “Tank” Covered Hopper – Sylvan Scale Models build

23869bexs - CP 383150 covered hopper (desk).jpg
A-lum-in-um? Al-umin-e-um? Aluminumumum?

This is the big kahuna. This is the final level boss battle. Anyone can slap a resin kit together and call it done, but if you can build one of these cars good, and I mean good, you can probably tackle 99% of the kits out there. The most challenging model I’ve built yet is the Sylvan Scale Models CP Aluminum “tank” covered hopper (yes, more challenging than the Funaro & Camerlengo flat resin CP “minibox” kit, or any Kaslo resin shell kit). An early design of the common teardrop or round-sided covered hopper cars all over North America today, they were built starting in the late 1950’s for CP and CN out of aluminum, and later evolved into a steel sided design.

One of these puppies makes assembling a Kaslo GP9RM shell seem like putting together a P2K mill gondola kit: sure there’s a lot of bits, but you have most if not all of the parts you need included (and they look and fit reasonably well), prototype photos are easy to find, and you don’t have to go ahead and do anything like scratchbuilding major components like end cages, or digging through tonnes of books and crawling the web for elusive reference photos. All challenges associated with this model that can make you want to put it back in the box and never speak hide nor hair of it again.

Some Background Info:

In 1959, Alcan and CN jointly developed a new type of hopper, one of a tubular design made of aluminum with rounded sides and no centre sill. It was also slightly shorter than the current rectangular “slab side” hoppers CN & CP were using, but of the same 3000cuft capacity. Made in 4 and 8 hatch versions, they ultimately lead to the later steel design cars, and the fully cylindrical cars purchased en-masse by many Canadian outfits. These earlier cars were given the nickname “tank hoppers”, and CN and CP both purchased aluminum versions made by MLW, Marine Industries and National Steel Car (CP did go on to buy the similar looking 3400cuft steel cars (painted black), but CN only bought the earlier aluminum ones). There were minor variations between the orders and builders, as well as CN vs CP cars (end air brake tanks, side tabbed brake piping mounting, skirting between the bays, re-enforcements welded to the side sills by the RR’s later on). Data suggests CP’s were off-roster by the late 80’s. CN’s lasted a bit longer, and they still had a few kicking around a few years back in OCS idler car or sand service (53390 series).

Photos of the CP cars themselves are difficult to find, but you can pick them out in trains because of their silver colour, compared to the plentiful steel cars that were painted black. Information suggests two uses they saw were hauling nepheline syenite out of the mines in Nephton and Blue Mountain, Ontario off the Havelock Sub, and in potash service out west. They frequently went south of the 49th parallel (two reference photos show them in Illinois, and Dallas TX hauling syenite. Other photos I’ve seen show them in Toronto ON (possibly being spotted at Redpath Sugar) and at Nelson BC.

Strutting its stuff in Illinois:

This one’s probably in eastern Ontario somewhere:

Common cargos hauled in this style of round-hatch covered hopper would be potash, sand, cement, fertilizer, sugar, salt, and nepheline syenite.

The Model:

Many pieces of oddball equipment are only available in brass or as resin kits, if at all. This model is one of Sylvan Scale Model’s out of production resin “tank hopper” kits, of which a few different CN & CP versions were made.

Back in March 2015, a friend alerted me to someone selling a pair of the unbuilt hopper kits on eBay for a reasonable price. 2 were available, so he buys one (a CN 4-hatch aluminum car) and I buy one (a CP 8-hatch aluminum car).

I had originally wanted to do one of the more plentiful black steel CP hoppers (CP’s aluminum ones were only aluminum, with markings/logos applied to them), but the kit was for the aluminum version and there is notable capacity difference between the two (3000cuft aluminum vs 3400 cuft steel) so one can’t substitute one type for the other. As well, It’s very finding good reference photos of CP’s aluminum cars – I’ve only found a grand total of 5 good photos, and only one in the multimark livery (but about half to a dozen photos of the CN cars…)

This is how many kits start off, and how many kits end up – sitting in their boxes either unbuilt, or half-built and put back out of frustration. The decals were included, but trucks and couplers are usually separate (the trucks here were a pair of spares slipped in by me).

After all the parts were verified to be present and included, they were given a cleaning using Sylvan’s resin prep solution to remove any leftover casting residue from the parts.

The parts were given a quick washing in some resin prep solution, then rinsed off and set to dry. It’s usually easier to leave the small bits together and trim the flash off later, lest any tiny pieces get lost or washed down the drain.

Now the fun begins…

On this model there was some unfortunate warping on the body. In addition to the roof casting being a bit warped both length-wise and width-wise, one of the sides of the carbody was cast thicker than normal, and sort of bulged out. Due to the thickness of the sides, there was no fixing this error with hot water and firm pressure (as one would with thinner parts). After a good amount of sanding and getting not very far I said to hell with it, and just lined up the slightly warped edge of the roof with the warped side of the carbody, marked them, and glued them together like that later on when the roof was done. Not entirely impressed with that, but it’s not overly noticeable unless you’re really looking for it (the second car I bought was a little better in this regard).

Bulging/warped resin bodies, Dan is not impressed.

After all that was sorted out, some basic assembly took place: the underframe piece with the bays was fitted and glued in, along with the two truck bolster/coupler box/frame members at the ends. Since this is resin, you can’t use regular modeling cement and must use some kind of cyanoacrylate adhesive (CA glue) or super glue. Don’t stick your fingers together!

The weight box was raided and the scale was brought out bring the car up to basic NMRA weight specs. The weights inside were spare bits cut off Proto 2000 GP9’s that received chop noses over the years. Since I wasn’t sure how well supergluing the weights to the slippery resin floor inside would hold up over time, I also drilled through the weights and into the floor, tapped the holes, and put in some long 2-56 screws in. A few bulk packs from China can be bought relatively cheaply, leaving one with literally tonnes of screws to burn.


Weights, always important, especially in a car that’s going to be “sealed” so no more weight can be added.

The roof was then positioned accurately and superglued on (I used pieces of styrene glued on the underside of the roof to help work out exact positioning before gluing the whole thing on) and then the roof hatches were glued on (with bits of styrene added between to simulate the hatch stops).

End Brake Piping:

It was decided to start building the end brake piping setup before tackling the end cages. This is where the trouble, guesstimating and excessive digging came into play, as photos of these cars are difficult to find, much less photos giving a good view of the end details. In all my travels over “teh internets”, I’ve been able to locate few good photos of these CP aluminum cars, and fewer still that give a good view of the brake piping setup behind the end cages (one low-resolution photo gives a poor view of the B-end setup). The CN cars are similar but again: few good photos, and there were differences in the air tanks, brake piping and rigging setups.

The instructions were of little to no help for this, as they didn’t match the single end photo of the CP aluminum car I dug up showing the B-end, and included no brake piping instructions or diagram. I think two of the end variation illustrations shown were actually mixed up too.

Working off what photos I had, I was able to put together some semblance of a brake system on the B-end bent from 0.015″ wire, including building a larger custom air tank for the top from a piece of spare styrene sprue that was rounded off, and make bigger mounts out of styrene for both air tanks. There were a few guesstimations made here and there.

20132bes-B-End.jpg Above shows the basic brake piping setup, a few more pipes need to be added before adding the end cages (see later photos). Most of the small resin brake system bits included were used.

IMG_5116e.jpgAll the end piping detail is applied at the B-end, the A-end is basically bare.

End Cages:

Turning my attention to the A-end, I found the stock resin end bars included to build the end cages to be too fragile, and the tiny styrene rungs also included not very durable. Initially I decided to drill out the resin bars for new brass wire rugs, but after installing them and not all the rugs lining up correctly, and having one bar break, they were all removed and it was back to the drawing board.

(I also found a little discrepancy in the Sylvan instructions: the CP aluminum cars only had one bar in the middle on both the end cage assemblies (slightly offset to the left), as opposed to two on the B-end of the steel cars (A-end had only one, offset to the right). The Sylvan instructions show two in the middle for all variations, and probably assume both ends are the same. Again, easy to miss all this due to lack of reference photos).

The solution in the end was to make new end cages using close-enough Tichy #3033 end ladders, brass 0.010″ wire and styrene 0.040″ x 0.040″ rod. The Tichy ladder rug spacing was a hair tighter than the prototypes, but otherwise a pretty good match. The ladders and rods all had holes drilled in the top and bottom ends for 0.015″ wire, which fit into holes I drilled in the car’s roof and floor ends, to make them more durable in the event something were to happen. The styrene rod is a bit more flexible and stronger than the somewhat brittle resin bars with the kit.

Drilling out both ends of the end bars and ladders for wire re-enforcement to be inserted at the tops and bottoms.

Various ladders and bars for making the end cages. The bottom ladders had one bar cut off, and would be butted against the bar of the latters at the top, to form the corner ladder assemblies. Note the bits of wire placed in holes drilled in the bottoms of the bars, which will fit into holes drilled into the bottom platforms of the car. Markings were made to show where to drill for the handrails/grab irons, and everything drilled before installation.

The bars on the side cage setup (non-ladder corners) that go above the stirrup steps were looped together at the bottom with wire, glued inside the frame above the stirrup area.

25697 - End railing installation.jpg
Ladders and bars installed, applying the end railings made from 0.010″ brass wire.

20147bs-SideGrabInstall.jpgSlipping some brass wire grabs in the non-ladder corners (all the holes were measured and drilled before installing the end cages, easier to drill them that way)

Parts were test-fit, and then holes were marked and drilled in the top of the roof and into the tops of the bars and ladders allowed bits of wire to be inserted and glued in, strengthening the end cage assemblies. They would be filled with putty and sanded smooth later.

Basic end cage assembly work done. This is the A-end (non-brake end), which is bare of brake details and piping.

(One interesting A-end variation on the aluminum and steel tank hoppers was CP (probably in the 70’s) torched off the upper 2 rugs of the side ladders and the corresponding half of the top roof grab (but left the adjoining end ladder and top grab intact). Probably a modernization effort similar to cutting down full height boxcar ladders, but leaving the end one intact for roof hatch access. See photo above. No rugs on the B-ends were removed).

B-end cages built up, with a little boo-boo after a fall that had to be rectified. Mistakes happen!

After the end cages were assembled, it was time to move on to detailing the brake wheel area and the brake rigging around the B-end. The stock brake wheel mount, walkway and Tichy brake wheel were used, but new longer platform supports were made from styrene. The brake rigging linkage was built using A-line chain and 0.010″ brass wire. The bottom rigging rocker was fabricated from styrene (CP’s aluminum cars had it mounted under the frame, CN’s had it mounted just above). Some extra brake piping was also run up the side of the car from underneath to inside the cages for the retaining valve. Again, the lack of photos means some of this had to be guesstimated.
That should do it.

Happily all this was only required on the one end (B-end).

The roofwalk was installed, wire roof corner grabs were drilled and inserted at the corners, and some roofwalk retaining straps made of styrene strip (and bent down the roof sides) were added. The roofwalk was a little short, so I extended it with bits of styrene, and installed some end supports (not shown however – I must have forgotten and installed them later prior to painting).


All is not over yet – some work is required on the underframe!

Piping, bays, detailed bits, etc!

The long brake piping on each end was bent from 0.015″ steel wire according to photos, and holes were drilled in the underside of the carbody near the trucks for the ends to fit into. The piping supports along the sides were made from bending pieces of 0.010″ brass wire around the piping twice, drilling holes on the underside edges, and inserting/gluing both ends of the wire into the holes. Bits of 0.010″ styrene were then glued in front of the supports, hiding the wire loops (on earlier aluminum hoppers like 383068 linked above, these extend a bit up the frame sides, but on later ones like 383202 they’re mounted fully underneath) . The wire loops give the piping a more durable mounting, and as many modelers grab freight cars by the underside edges, will hold up better to regular handling. The Sylvan kit instructions suggest making these piping supports out of paper bits (yes, really, check the instructions), which probably won’t hold up that well over time.

Some 0.010″ styrene was added to make the trim around the bottoms of the bays on both sides. This detail differed from side to side, and photos suggest the left sides of the bays were more bare, while the right side had some additional bay bracing (added from styrene bits) and the shaker brackets (which were added from the kit). These aluminum hoppers also had additional skirting between the bays, but the photo of the CP Rail livery car I was building appears to have had them removed (torched out for better underframe/gate access?), and this kit version doesn’t include them either, so it wasn’t a concern (the skirting should be added for CP script cars and CN though. I think the CN Sylvan cars have the skirting cast into the underframe part).

Brake piping as viewed from the sides.

The bottom discharge assemblies were glued on the bay bottoms, and the gate opening bars/cranks were made from 0.015″ wire glued on the inside, with bits of styrene sprue drilled and glued on the ends.

Left side bays closeup.

Right side bays closeup.

Also note, thin strips of 0.010″ styrene were glued to the underframe undersides near the truck bolsters (visible above the trucks). These appear to have been re-enforcement gussets or something similar welded to the underframes by the bolsters (CN did something similar with their cars too – always work from photos!).

22462bexs-End Details.jpg
Closeup of some of the extra end details added.

Other small bits added to the ends/underframe were the stirrup steps (Tichy parts, included in the kit), stirrup step bracings and coupler lift bar mount (made from thin styrene bits), U-shaped bolster plates on the bolster ends above the trucks (cut from thin 0.010″ styrene sheet), end grab irons, and two small tack boards on the bottom frame near the bolsters on both sides (Branchline parts).

Ready for Painting

Some photos of the “undecorated” detailed model, almost ready for the paint shop.

22460bxs - CP 383150 tank covered hopper.jpg
B-end, right side of the car.

22461bxs - CP 383150 tank covered hopper.jpg
A-end, right side of the car.

22458bxs - CP 383150 tank covered hopper.jpg
B-end, left side of the car.

22459bxs - CP 383150 tank covered hopper.jpg
Yep, yet another shot of all the B-end detail. The A-end is basically like this but devoid of all the details except end cages and handrails/grabs, as shown in another of the above photos.

The trucks and couplers were removed , and the car was given a wash in soapy water and a good rinse to remove any hand oils prior to painting.

Paint Shop Time

The car was given a good coat of grey primer in preparation for the silver. These cars were unpainted bare aluminum, and usually weren’t very shiny (more of a dull silver and often having a dull weathered look). I mixed a custom batch of Tamiya flat aluminum, medium grey, flat white and thinned with all with distilled water for airbrushing. After spraying on a few coats (pay attention to the nooks and crannies in the end areas), the car was clear-coated with True Line Trains Gloss Glaze acrylic paint (although TLT has discontinued its paints, Testor’s Model Master gloss and semi-gloss clear acyrlic is similar. Information suggests that TLT paint was done by Testors/Pollyscale, and is basically Pollyscale paint made to Canadian colours).

22882bxs - CP 383150 silver painted tank covered hopper.jpg
“We can has silver!”  Painted, needs some clear, and then decal time.

The multimarks were then masked and sprayed using my usual method (described here). A note that on black and silver cars, CP painted the triangle red instead of black.

The Sylvan CP Rail livery decals that came with the kit were a bit on the thick side (in terms of the decal film – even after multiple coats of clear, you can still pick out the film glint), so Microscale decals from their generic CP Rail freight car set were substituted when possible (for the larger lettering and roadnumbers) and the Sylvan decals were used for most of the data. If one is doing a script car, I’d probably advise finding a Microscale set (their silver pressure unloading covered hopper set might work). The reflective triangle decals came from a Black Cat CP boxcar set, and the COTS block from a Highball set. Once all the Microset/sol setting solutions were dry, everything was sealed with some more clear.


23847bes - CP 383150 finished, 408pm.jpg

23841bes - CP 383150 finished, 406pm.jpg

23849bes - CP 383150 finished, 409pm.jpg
“Work that catwalk, girl!”

Final details applied/reapplied: the appropriate trucks were Walthers 70-ton (ASF?) trucks, borrowed off one of their Canadian bulkhead flatcars, with Athearn 33″ metal wheelsets painted a rust colour (you might have noticed some earlier photos taken have a pair of generic Accurail trucks in their place, used as temporary “shop trucks” during the build process). Kadee #58 couplers were also painted and installed at the ends. Everything was drilled and tapped for 2-56 3/16″ screws (the resin is a bit soft, so for a more durable screw hole you can drill out the holes larger, superglue a piece of styrene rod or sprue that fits in, and drill and tap the middle of the styrene rod. I’ve had to do this with a few cars whose truck screw holes were stripped out in the past, but coupler boxes can be a bit shallower and harder to do).

Reviewing some of this now, it seems I forgot the end air hoses and cut levers. But not to worry, I’ll get around adding them to CP 383150 when I add them on a sister 383xxx car currently under construction (to be done in the script livery)…

29122bxs - Sylvan Resin Tank Covered Hoppers.jpg
Cloning: it’s not just for sheep anymore.


About mrdan8530

The power of a thousand monkeys on typewriters is all for naught without the knowledge to pen.
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2 Responses to CP Rail Aluminum “Tank” Covered Hopper – Sylvan Scale Models build

  1. Nice work! I had a pair of the Sylvan slab side hoppers that I threw out in frustration, so I can relate to your story.



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