The Gr670 4-6-0 CabForward Compound.

Updated: 19 Dec 2001
Back to Home PageBack to The Loco Index
This does appear to be a logical way to build a locomotive. You can see where you're going, for one thing. However, steam cabforward designs have been rare.
I have data from two books saying it was designed by Guiseppe Zara, and one saying by Frescot; I will dig deeper.

Left: The front of a Gr670 4-6-0 Cab-Forward.

The 4-6-0 was a 4-cylinder compound on the Plancher system. There were two LP cylinders on one side, and two HP on the other. To fit them in, one LP cylinder and one HP cylinder was mounted between the frames.

The firebox was above the front bogie.

Above: The rear of a Gr670 4-6-0, showing two LP cylinders this side, and two HP on the far side.

This 4-6-0 locomotive was designed in 1900, for the Southern Adriatic railway. A prototype was exhibited at the International Railway Congress in Paris.
It must have been a success, because locos of this design were working the most prestigious Milan-Bologna expresses in 1922, and in 1932 were still working on the Milan-Verona-Venice run. They finally ceased work in the early 1940's.

Left: The loco with its tender.

The tender was a cylindrical tank and carried only water.

This loco was a four-cylinder compound with side coal-bunkers, which look rather small in capacity. Apparently coal was also carried on the roof. The difficulty of getting coal from a rear tender seems to have been the major disincentive to building the cabforward configuration.

Above: The Gr672 was a 671 adapted to the Franco-Crosti boiler system.

The idea behind the Franco-Crosti boiler system was to make better use of the heat remaining in the exhaust. The firebox gases go through a normal boiler and then a preheater, which heats the feedwater before it reaches the boiler. Here a big pipe carries the hot gases from the boiler to the preheater which has replaced the tender. The exhaust steam from the cylinders is piped back to a blastpipe just below the chimney at the rear of the preheater.

See Franco-Crosti Boilers for another photo.

Above: The Franco-Crosti Gr672 4-6-0 with its casing in place.

Back to Home PageTop of this pageBack to The Loco Index