Wagon Construction - Building the Parkside PO Mineral Wagon Kit (PS33)

Prototype History

The design of this wagon originates from the 1930's and is basically a version of the 1923 Railway Clearing House (RCH) Specification 12 ton coal wagon with a steel chassis. Steel chassis had been used from the 19th century and were relatively common before for WWI, however, due to the economic situation following WWI and through the 1930's Depression, construction had reverted to wood. Following the Depression, steel regained favour due to its lower maintenence costs.

These wagons were fitted with side doors for manual discharge, bottom doors for gravity unloading and end doors for tipping which was typically done by coal users at coal shipping docks.
It was well known for these wagons to spend long periods of time idle, either due to lack of traffic during the summer or standing at ports awaiting shipping orders.

Capacity was originally 12 tons but was increased to 13 tons during WWII. At the beginning of WWII, virtually all privately owned wagons were taken over by the Government where they remained until reallocated after the war, in this case, to the National Coal Board in 1947. Many of the fleet were subsequently sold to British Railways.
The steel chassis wagons were the best which BR inherrited and these survived into the 1960's. Those used by the NCB were classified as 'internal users' and continued to be used until the 1980's.

In BR ownership, these wagons had their numbers prefixed with a 'P'. This was not related to their previous ownership as they were simply taken from blocks allocated to the different repair shops when the wagons came in for attention.

The Kit

This kit was originally available under the Parkside Dundas brand, but since Parkside have been taken over by Peco, it is now sold under the 'Parkside by Peco' brand.
Like all Parkside kits (and most 7mm scale kits for that matter), this model is supplied in a box which is suitable for storage of the completed model.
When opened, the box contains a collection of packages containing all the parts necessary to complete the model. Wheels are supplied as are sprung buffers, couplings and transfers. All that is needed to complete the kit is tools, glue and paint.

Getting Started - Building the Chassis

When building any rolling stock kit, I always start with building the chassis: get this straight and sorted from the beginning and the rest of the kit will go together nicely. If the chassis isn't square, the model can never be square and will have all kinds of running problems for ever more.
This kit utilises the standard Parkside pattern of axle boxes prototypically moving up and down within the W irons as a means of compensation. Two plates form the axle box and 'sandwich' the W irons, with a cover on the outside and a brass bearing (supplied) is pushed into the back, thereby retaining the whole assembly. The W irons are separate to the solebars. The following shows the completed axlebox assembly:

The solebars are then attached to the underside of the floor and fixed against the underframe detail.

And then a serious problem arises:

It becomes very quickly apparent that the solebars are too far apart for the axles to fit properly, resulting in approximately 2mm of side-ways 'slop' in the wheels within the bearings.
The model cannot be built by following the instructions.
Given that these kits have been available for a large number of years, it amazes me how such a major manufacturing fault has managed to survive for so long without being rectified! Not only that, this is such a major fault, that it proves that whoever designed the model has never tried to build it because if they did, this fault would never have reached the market place. Given the price of these kits, this is really unacceptable.

At this point, I should note that I have come across other Parkside kits with the same problem. I resolved the matter on those by using washers:

Please note that 'optics' are causing the solebars to appear not to be at right angles to the floor.
While this method works, it is not entirely satisfactory as the axle ends are not fully inserted into the bearings.

I considered other options which I have used in the past:

  • Bending the W irons inwards. This results in them not being at right angles to the frames. Unfortunately, the amount of bending necessary to resolve the problem on this kit is so much and results in too much visual distortion for this to be a viable option
  • Not fully inserting the brass bearings fully into the backs of the axle boxes. If one follows the instructions, it will be too late to use this solution when the problem is identified! Even if one is aware of the problem, the fact that the axle boxes have a certain amount of movement in them anyway, makes this solution very fiddly to set up and adjust correctly

I settled on a very simple solution of fitting .2mm evergreen strip on the backs of the axle boxes as a 'spacer' to hold the bearings further out of the axle boxes:

In hindsight, a better option might have been to fill in the bearing recesses on the backs of the axle boxes with plastic strip as the above solution results in slightly too much packing.

The following pictures show the completed model, ready for painting.

One aspect which I missed in the instructions was the order of assembly when it came to the brake hangers. The kit is supplied with parts which must be threaded onto the brake rigging before it is fixed to the wagon. Because I missed this, I had to fabricate suitable hangers from wire as shown below. This is not actually a bad thing because the wire results in a stronger assembly.
One of the side effects of the contruction method of the brake rigging is that it is possible to make the handbrakes 'operate', something not really possible in smaller scales:


I model British Railways Western Region practice as it was in the early 1960's. These wagons survived into that period. The wagon body will be painted in BR unfitted freight grey and the chassis will be well weathered as will the whole wagon.
Here is the completed wagon at different stages of painting, firstly, the inside having been painted with Railmatch 412 Weathered Black and the chassis with my frame dirt mixture of Humbrol 113 and Tamiya XF1:

The following image shows painting having been completed and masking in place for painting the black lettering panels:


Parkside kits are provided with what appear to be waterslide transfers. These were duly applied. To add some difference, I painted a few planks in a timber colour (Humbrol 121) to represent planks which have been replaced, but not painted - in the latter years of the lives of these wagons, unpainted planks were very common. Note that I have also painted the ends of the planks on the ends of the wagon - planks don't just stop at the edges of the sides! During weathering, the planks will be appropriately toned down.
The white diagonal lines which indicate the opening end of the wagon have been painted on as it is impossible to attach transfers to surfaces with protruding rivets. I have no idea why a manufacturer would even bother supplying transfers for this situation because they can't even be applied!


My standard method of weathering is to use Carrs modelling powders as described in article Weathering Wagons.
Before weathering could commence on this model, I needed to protect the transfers and to that end, I sprayed the model with an acrylic matt varnish.
Black coal dust was applied all over, in some areas heavier than others to give a patchy, irregular finish. This also had the effect of toning down the 'unpainted' planks.

The Completed Model

Following are a few images of the weathered and completed model. Please note that these photos were taken under artificial lighting conditions. In natural light, the weathering appears darker.


Like all Parkside models, this one makes up to a really nice model, but the issue with the chassis would likely be a 'show stopper' to many building this kit. It really makes me wonder how many people actually successfully complete this kit!
I believe that Peco could improve this kit by fixing the manufacturing fault with the chassis so that it can be built properly according to the instructions.

In summary, this kit makes up into a lovely model, enjoyable to build and represents a useful addition to any layout with any form of coal facilities. Recommended.

Related Articles

Index of Articles
Weathering Wagons

Graham Plowman (Created on 3/7/2020, modified on 28/06/2021 10:24:38 AM +10:00)

Post Script

The issue of the sideways 'slop' of the wheels was taken up with the Peco Technical Advice Bureau. Their response was as follows:

"Dear Mr Plowman
Thank you for your email
I have spoken with our Sales Manager, and we have both investigated this in more detail. The axle sideplay is necessary due to the assembly sequence which requires the W irons and solebar assembly to be glued to the chassis floor and sub chassis, before the wheels are added once the glue has set. If the axles were any longer it would prevent the wheels being inserted in place. The sideplay does not affect how the completed wagon will run on the track. Looking at your photos it would seem that the solebars and W irons are slightly out of vertical which would accentuate the sideplay of the axle. With the solebars it is always best to run a flat file along the top edge of each one to ensure it is flat and at 90 degrees to the rear face of the solebar so that it will sit vertical on the floor.

Kind regards
A Beard

PECO Technical Advice Bureau

I would suggest that there are several problems with this response:

  • If The Sales Manager and A Beard had actually built one of these kits, they wouldn't respond in this way!
  • The suggestion that a chassis is constructed and wheels inserted afterwards is extremely poor advice because it results in a chassis which is not square, a model which wobbles on the track and wheelsets which do not run perpendicular to the rails. The suggestion that sideplay does not affect the completed model running is simply rubbish.
  • Sideplay is only necessary if one promotes a poor constuction method
  • Real railways have minimal sideplay because extreme wear may result

Kit supplied by: Tower Models Logo  and   Parkside

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