[Boris The Spider]

Cool stuff!

What was the 'roundhouse' used for?

The Roundhouse was a shed for Locomotives with a turntable in the centre ......more usually they are only a half-circle...the present-day one is only a half-circle type

To elaborate further...
Steam engines could only run effectively forward and weren't designed to pull a consist of cars in reverse for any length of time. Therefore at the end of a route the engine needed to be turned around. Now if that's all you wanted to do a simple triangle of track called a 'Wye' was all that was needed.



At major rail yards engines would be serviced and overhauled. That required a shop building. The roundhouse with it's turntable provided a compact way to do that and also served to turn the engine around.

With today's diesel engines that can be ran just as effectively in either direction the turntable and roundhouse have all but disappeared.

Here is all that is left of the only roundhouse in my home town:



[i]The 1ST Brooklyn Roundhouse was built in 1912. It was at the Southern Pacific Railroads northern most terminus. The end of the line.

The existing roundhouse was built during World War II. The original brick roundhouse was torn down in 1956. Portland