a question about turntables

[Mark300]

javern,

Generally the term is 'concrete' rather than cement; This is construction's version of calling a rifle a gun or a boat a ship. [:)]

Concrete became a popular technique for forming ciruclar retaining walls and foundations simulateously (particularly on dry land unlike bridge abutments) in the late 19 and early 20th centuries. Prior to that brick masonry was used ALTHOUGH...if the railroad had a good brick supply then pit construction for some roads may have continued in brick masonry. Wood just rots in a few years and unless the road was lucky to have used cypress or cedar, then the pit had to be rebuilt or abandoned.

Agreed, the pit surfaces are generally open graded and filled with stone or gravel for drainage (accept perhaps in regions prone to movement do to undermining like in floods or earthquakes; then concrete slabs are used in the floor of the pit to pin the foundations and keep the thing 'circular'). Has anyone from regions affected by flooding or earthquakes seen concrete bottomed turntable pits?

It's easy enough to model brick masonry or concrete when considering a turntable pit. If your in a region where the buildings on your railroad were wood framed, steel or concrete constructed then it's a good bet the bridge abutements, retaining walls and pits (like turntables) would be constructed with concrete,

However...it's your road and anything is possible in model railroading!

HTH

Mark

[cacole]

The two turntables I remember seeing when I was young had concrete around the pit edges and a large concrete support pier in the center. The floors in both were cinders so rain and snow could soak into the ground. This was in the late 1940's to early 1950's at small town roundhouses on an Illinois Central branch line and a Missouri Pacific division point.

[Anonymous]

Yes, I've seen more concrete than any other material. I've also seen tibers and brick used for pit walls. Most of the hobby manufacturers sell the concrete version.

[Javern]

are turntable pits generally made of cement? [:)]