Hi Don, apparently not - the barrel was counterweighted as per Schneider practice. Schneider didn't set the trunnions back like Krupp did and didn't use equilibrator cylinders. In fact on the Schneider guns the trunnions were close to and slightly behind the centre of mass of the barrel so they used counterweights above the breech to balance the barrel. I think the length of track on the ground gave a stable firing platform so they didn't have to worry about balancing the mass of the gun. The SPG also had no suspension so it would be pretty solid on the ground. The St-Chamond SPGs were similar - the 194mm gun version didn't have any counterweights and seemed to be a pretty stable firing platform - although it did roll back about a meter or so for every shot - there is a video of the Saint-Chamonds firing in 1940 (link the article referenced below).
Hi John, The Schneider was self-contained - it had a 6-cylinder 135hp engine driving a generator. It also had an auxiliary 4 cylinder engine to drive the traverse gear (no idea how that worked) and other stuff. The Saint-Chamond SPGs used two vehicles - a tractor with engine and generator and the gun vehicle driven with electricity from the tractor. The Schneider SPG couldn't carry ammunition beyond perhaps a couple of rounds or many people so it was dependent on a munitions vehicle (maybe a Schneider CD?). There's an article on the Saint-Chamond SPGs at
Landships II. There's hardly any information on the Schneider SPG in English - even the French historians didn't know much about it until some recent work in the French Army archives.
Regards,
Charlie