Does anyone know of a locomotive that is or was equipped with rocking grates for a firebox of 3' x 8'? From that does anyone know of any drawings for ones that size?

If I include the pre-designed dump grate, the size comes down to about 6.5' x 3'

This is for a locomotive with a firebox that is in between the frames

Old Maude - the 1880 Baldwin roundhouse switcher from the Central of Georgia Macon shops has a long and narrow keyhole boiler which is probably not quite that long or that narrow, but gets pretty close - so close that the technology can be adapted provided there's room between the mud ring and the axles for the grate assemblies and ash pan. Next time you are in Savannah drop by and crawl in and check it out. The narrow gauge old lokies at Colorado Railway Museum in Golden are also pretty long and narrow. A deep firebox seems to be a constant in this application.

If not within the railroad community you may try reaching out to the traction engine folks. How many grates are in the set? Do you have the grate bearers? Three feet wide would not be much of a problem but how many grates are needed to cover the eight feet? On your side of the pond the folks who work with the showman's and plowing engines may be a good resource....mld

I'm amazed at how grates are one of those things that don't get much ink on the in the old cyclopedias, etc...... no joy so far.

How they work: rocking grates are usually made in either the table with holes in it style or the interlocking fingers style. Each section is cast separately, and includes as trunnion in cylindrical form protruding from the sides of each at center. These ride in U shaped divots in the grate bearers which are mounted to the mud ring, so each separate grate section can tilt on a central axis. The grate sections also have a lever cast onto them protruding downward into the ash pan with a hole towards the bottom. Linking these levers together through the holes with a long bar ties all the grates together into one unit so they all tilt the same amount at the same time. The bar extends back through an opening in the ashpan to tie into an actuating lever which comes up through a hole in the cab floor - the fulcrum of the lever is generally at floor level. Many of these levers are made in sections, so the stub end coming through the floor is short and an extension fits onto it when you want to rock the grates. The grates can be rocked from gentle rocking to wiggle out ash to wide opening to dump the fire over the ashpit at the roundhouse depending on how far you move the lever. Most of the grate sections are about a foot in depth front to back, and fill the firebox between the bearers from side to side.

Larger locomotives with bigger fireboxes have more than one series of grates which are separately actuated. A TUYERE type of grate was also used which consisted of cast bars which had cored air passages and fit over transverse holders to compile into a grate section - a difficult and complex style you don't need to pursue. The Reading T hogs had these........

I'll see if I can find a drawing or two in newer books than the 1880 era ones I've investigated so far.

I have drawings for rocking grates which are 45" x 73.25". I would need to ask if I could share them or modify them as I have the original drawings and have them in 3D CADD.