The 155mm Long Tom was a field gun used by the US Army during World War II and Korea. Many artillery pieces have been nicknamed "Long Tom" throughout history but it is this 155mm long-barrel towed field gun that is most commonly associated with the name. Originally designed by the French in World War I, it was modified for US use as the M1 155mm Field Gun, followed by the M1A1 used for coastal defense and corps artillery battalions. In 1940 the gun was modified and improved once again and a two axled, eight-tire carriage was added (10 tires, counting the 2-wheel limber). This version, the M2 155mm Field Gun (pictured here), was the backbone of heavy artillery in the US military in World War II with thousands serving in both the European and Pacific Theaters. During World War II the Long Tom's standard prime mover was the massive Mack NO heavy truck or later the M4 or M5 High Speed Tractor. The Long Tom weighed in at 30,600 pounds and fired the same 95 to 100 pound high explosive, smoke and gas projectiles as the 155mm Howitzer, but with increased range and accuracy. It was designed for indirect fire at ranges of 10 to 14 miles, but has been used for direct aimed fire under extraordinary circumstances. Each Long Tom required a combined crew of 14 or 15 men to move and operate. It took about 30 minutes to ready the Long Tom upon arrival at a firing position.
"155mm Long Tom." Olive-Drab.com. August 15, 2009. Oct. 6, 2010. http://www.olive-drab.com/idphoto/id_photos_m2longtom.php