The first "Defender" delivered to the U.S. Navy was in 1938. They produced more than 5000 "Defenders" by early 1945.
The Defender was used in three wars: WWII, Korea and Vietnam.
The production of the Defender continued long after the end of the Hall-Scott Company. (The "Invader" was the father of the Defender, as was the 400 series commercial truck engine)
The engine weight was any where from 3,600 pounds to 4,600 pounds, depending on the version of the engine.
Some versions of the Defender had a compression ratio of 7:1. It came with a 24 volt system.
The first Defenders had a displacment of 1996 ci. w/ 575 H.P. When the Navy asked for more power, Hall-Scott put a supercharger on it and the horse power increased with 100-125 more horses at 2281 ci. with a larger 5 3/4" bore x 7" stroke. This version had well over 700 H.P.
Defenders were used in many different boats, from air rescue to the Fairmile. After WWII, Hall-Scott marketed the V-12 as a stationary engine.
The women of Hall-Scott showing unity and support during WWII
The above boat is a 85 foot rescue used by the Navy and Coast Guard during WWII.
They ran on V-12 Hall-Scott Defenders.