I just did a short research (wiki and a few other sites) for the French steam locomotives used between 1914 and 1918.

There are a huge variety of different type. Focussing on the North and Eastern region, here a list of the most common models:
030 Est - "Mammouth"
130 A Est - "Mogul"
130 B Est - "Mogul 8s"
230 A Est - "Ten Wheel"
230 B Est - "Ten Wheel"
230 J Est - "Ten wheel série 11 S"
140 Est - "Consolidation"
232 T Est - "Baltic"
140 C ALVF
050 T Midi - "Ten coupled"
220 Nord - "Outrance"
221 série 8v - "Atlantic"
230 Nord - "Ten Wheel"
230 G PO - "Ten Wheel"

The first 3 numbers means, form first to third:
- number of wheel boogie before motorized wheels
- number of motorized boogies
- number of wheel boogie behind motorized wheels.

Some pictures of some models:

030 Mammouth


130 Mogul


230 Ten Wheel


140 Consolidation

(The coal tender is not original, it was replaced later)

232 Baltic


140 ALVF

(mainly used in WWI for artillery transport)

220 Outrance


221 Atlantic
A full page about the Atlantic There

230 G PO
Wikipedia page about this locomotive There

And to finish, a very good site with lot of other locomotive picture of this era: There