Holt Mark IX

Construction of the Mk. IX SPG began in 1921. This vehicle was based on lessons learned from the development of the Mk. VI and was purposed to improve on the design. It was to mount the French Canon de 155mm GPF, which the United States purchased and renamed the 155 mm Gun M1918. The tank was powered by an unspecified 250 hp engine which could propel it between 12 and 16 mph.

However, the vehicle weighed more than 20 metric tons. This was considered too heavy and development of the vehicle stalled in order to try and make it lighter. This would result in the Mark X SPG.

Not much else is really known about this tank, so we're going to have be a little liberal here. I think the top engine from the Holt Mk. X can carry over as a stock option and we can give the 250 hp engine the top spot. As for guns, we can easily give this tank the M1918M1 as a second option. This is really nice because the same gun is already used as the stock option on the M12. Other than that, because there's a "range" for the vehicle's top speed, we can give the lower and upper bounds to the stock and top suspensions, respectively.

At Tier VI, this is perhaps one of the more frightening SPGs in the game. It's large and slow, but it has a very accurate and damaging gun for its tier. In line with the rest of the Holt SPG branch, this tank should have a poor reload speed and/or aim time to help balance it, however. Armor on these "tanks", while unknown to me, should be practically nonexistent—even for something as commonly unarmored as an SPG.

Guns: 155 mm Gun M1917; 155 mm Gun M1918M1

Engines: Sterling 150 (150 hp); Holt 250 (250 hp)

Suspensions/Alternate Hulls, Total Weight (metric tons): Holt Mark IX (21.7); Holt Mark IX Improved (21.7)

Hull Armor (mm): ??/??/??

Top Speed: 20 km/h (Mark IX); 26 km/h (Mark IX Improved)

Crew: 6 (Driver; Gunner; Loader; Loader; Commander; Radio)



Parent: Holt Mk. X
Children: M12

Sources:

http://landships.info/landships/tank_articles.html?load=tank_articles/Holt_SPGs.html#