Petiet A111A

The Petiet A111A was a locomotive design that was designed by one M. Petiet, Only eight examples of these steam locomotives were built between 1862-1863.
==The Locomotive==
The idea behind the Locomotive Petiet A111A was to double the output of a Crampton-type locomotive, but without coupling together two driving axles. Apparently at the time coupling rods were not considered strong enough to handle high speeds. Hence there are independent driving wheels and cylinders at each end, while the smaller wheels in the middle just carry part of the weight.
The amount of this weight available for adhesion must have been limited. The long drum on top of the boiler is a steam dryer, not a feed heater, which accounts for the presence on top of it of a little box that presumably holds the regulator, just behind the forward sand container. The chimney runs through the dryer, and exhausts just ahead of the cab. There is swiveling cover for this chimney; this was known in French practice as the capuchon (cap) and was used as a draught damper as well as to keep the rain out.
There was no feedwater heater and no injectors. The boiler was fed by a pump powered from one of the driving axles. The two big square boxes are clearly for sand, and there seems to be no steam-dome as such, the dryer presumably rendering this redundant. From the regulator box a large pipe appears to feed steam to the forward cylinders. Behind this a conical thingy holds two Salter safety valves.
All eight examples of the Petiet A111A Locomotives were scrapped.
Category:Duplex locomotives
Category:French locomotives
Category:French steam locomotives
Category:Tank locomotives
Category:Scrapped locomotives
Category:Steam locomotives
Category:Built in 1863
Category:France
Category:Built in 1862