PlaceLayers › Glossary › Railroad yard / roundhouse
What does “R.R.” mean on a Sanborn map?
R.R. is one of the ways a Sanborn surveyor lettered railroad yard / roundhouse onto a building footprint. Sanborn abbreviated hard, because the words had to fit inside the building.
How it appears on the sheet
R.R. ROUND HO. ENGINE HO. FREIGHT HO.
Turntable circle, fan of tracks, engine house with pits.
Why people look for it
Locomotive servicing areas are a documented historical use category. That is a reason to read the sequence of editions rather than one sheet, and to ask an environmental professional what it means for your transaction — not a finding about any property.
Reading it properly
- Note the edition year. The lettering describes that year only.
- Check the previous and next editions. A use that appears once may be a survey artefact; a use across three editions is a pattern.
- Read the neighbours. Adjacent uses matter as much as the parcel itself.
- Take the sheet, with its citation, to a qualified professional rather than a summary of it.
Browse Baltimore sheets Full decoder
A word on a map is not a finding. It records what a surveyor was
told or saw on one date. It does not establish how a site operated, or what is in the ground.
Methodology and limits.
Other terms
- Filling station / gasoline
- Auto repair / garage
- Dry cleaning / dyeing
- Coal gas works / gas holders
- Foundry / iron works / metal plating
- Blacksmith / wagon works
- Paint, varnish, oil and chemical storage
- Laundry
- Printing / lithography
- Planing mill / lumber / saw mill
- Tannery
- Ice plant / cold storage
- Coal yard / fuel oil