A proprietary type of grate bar for coal-burning locomotives. It was a standard sized casting which was assembled in a certain amount (8-12 or so) to a carrier bar, which equaled one typical large grate casting. An application for a typical locomotive might havd two or three rows, with 6-8-10 or so sections per row.

The advantage of the Firebar grate "unit" was that if a "unit" was damaged/burned/lost-into-ashpan, it could be replaced, whereas the one-piece grate casting was junk if a corner was burned off.

Hulson "Tuyere" unit grate castings were a similar and competitive item.

Howard P.

NKP 765 uses them.

The Valley Railroad bought the unit grates from UP 3985 when it was converted to oil burning in the early 80s; they are used in eng. 40.

New Hope #9 had them as well.

Howard P.

Greetings:
Valley's 40 and 97 are so equipped.
Each firebar weight about 8-1/2 lbs. and the carrier about 40 lbs. vs. over 100 lbs. for a single gratebar, so in addition to a cost savings in only having to replace one small section in the event of breakage, the labor involved isn't back breaking (not an insignificant issue for us as we get older...)
Most is not all of the operationg locomotive at Steamtown also use this type of grate.
J.David

Also equipped is ex-Union RR #77 / ex-M&NF #14 / ex-Tombstone Jct. #77 / K&T #14