The Depression, with its accompanying unemployment, was still dominating the economy in 1940, but the threat of war initiated major military construction programs. In the spring of 1941, Lockwood & Andrews, along with the consulting engineering and surveying firm of David M. Duller, were awarded the engineering contract for the San Jacinto Ordnance Depot.
The San Jacinto Ordnance Depot occupied a site of approximately 5,000 acres, located along the north side of the Houston Ship Channel across from the San Jacinto Monument. Carpenters Bayou flowed through it near the downstream end. This site has been converted to present-day Jacinto Port.
Because the world crisis situation leading to World War II was escalating, many buildings and services had to be designed and constructed quickly. Bill Andrews stayed at the downtown office while Mason Lockwood took direct charge of the engineering at the job site.
A slip was dredged with wharves for both ships and tugboats. Two hundred igloos of concrete barrel arch construction topped with layers of earth were built for ammunition storage. There were miles of concrete roads, a network of railroads and a railroad yard.
The shop area included a locomotive shop, carpenter shop and shops for other trades. There was an administration building, fire station, many warehouses and a residential area of brick houses for Ordnance Department military personnel. The Depot had its own water wells, distribution system and treatment plant and electric power and natural gas distribution systems.
The engineering and inspection work was handled well, and the job was successfully completed. It greatly enhanced the reputation of Lockwood & Andrews.