If someone had told me as a kid that I could build my very own steam engine, I probably would have believed them. Granted, I was pretty gullible, but I wouldn’t have been any less excited. Here I am now with a stupid grin on my face. This is the MSS Side Tank Loco, and it’s a dream come true.
So what exactly is this engine? Long story short it’s a steam engine, but tiny. For reference the boiler is about the diameter of a pocket-sized can of WD40 or one of the extra small cans of soda, but twice as long. Buffer to Buffer this loco is 8 1/2 inches long, and just short of 3 inches wide. Compared live steam engines normally found in the US this thing is tiny!
If the styling of the loco wasn’t a dead giveaway, then that last sentence would have been. This engine is an imported model from the United Kingdom. For whatever reason small scale live steam engines never caught on in the US. The smallest you will usually find is 3 1/2 inch gauge models. (gauge is just the width of the track.) O Gauge engines are very popular in the US but live steam in that size just never caught on. So this model is an oddity here.
Styling wise the MSS is a bit strange, as it is not based on aF particular engine. The closest prototypes would be Welsh narrow gauge locomotives, but no particular engine is a perfect match. The design of the MSS Side Tank actually goes all the way back to 1979 with the Mamod Sl1. There are few differences with these models other than namesake, the option of a diamond shaped chimney on the SL1, and the exhaust pipe. These models are so similar that parts are completely interchangeable.
As far as individual parts go, there are some standouts. The MSS features double-acting pistons. This means that the pistons provide power on every stroke in either direction. This was uncommon when the design first cropped up, and is still a nice touch today. Another curious thing with the pistons is that they are oscillating. This is incredibly rare on steam locomotives, model or not. This eliminates the need for valve gear but tends to hurt efficiency. The oscillating pistons make for a cool curiosity but takes away from the model’s (relative) accuracy. Finally, as one last feather in this model’s cap, the steam dome is functional.
Of course with this model you get intimately familiar with every piece of the engine. This unit is kit built, meaning you get a box of bits and some instructions. Beyond that the rest is up to you. There are pre-built units available, but that’s no fun. This loco is in that sweet spot of simple to understand but hard enough to be fun to assemble. After assembling this kit, there is the matter of running in.
Running the Side Tank Engine is an exercise in patience. First you need to check that everything is working correctly. Does the safety valve work? Will the whistle stick? Is the burner on the whole way? There are all kinds of little things that need checked. Then comes oiling all the moving parts. Next the boiler needs to be filled just right. Then the denatured alcohol burner needs to be filled perfectly, and carefully. (note: the MSS engines come with solid fuel burners, but a burner change is almost mandatory if you want to be able to get fuel in this country) Any spilled fuel could turn into a flash fire in a heartbeat. After all of that the fire can be lit and the 5 minute wait for the water to boil can begin. Once the engine has reached at least 7 psi (it maxes at 10 psi) then you can start running it… for about 15 minutes. That time is assuming you don’t stop partway through the run to re-oil like the manual suggests. With a dead-leg oiler upgrade you could run for the entire 15 minutes with no interruptions.
While running these locos you are always in for a show, for better or worse. When run for the first few times steam engines need time to settle in. Water and steam will leak a bit for the first few runs before the engine is finally run-in. After being run-in the MSS will purr like a kitten while running, albeit an energetic one. Ever since the early 80’s this design has had a reputation for running away when on the tracks, and the MSS Side Tank Engines are no different. These engines just don’t do “slow.” The weird regulator/reverser block that controls these engines just is not built for it.
A slow engine is a very big deal to people that are into model railroading. A model like a Mamod or MSS poses a challenge for modelers. How do you tame an engine that just wants to run away? That is a blog for another time.
Remember to leave a like if you enjoyed this post and leave a comment below. Subscribe for more content like this and remember to share this post with people who might enjoy it.