155 mm Long Tom

Infobox Weapon
name=M1 155 mm Long Tom


caption=Long Tom in travelling position, US Army Ordnance Museum.
origin=United States
type=Towed field artillery
is_ranged=yes
is_artillery=yes
service=
used_by=United States, Austria, South Korea, Taiwan, Turkey
wars=Second World War
designer=
design_date=1930s
manufacturer=
unit_cost=
production_date=
number=
variants=
weight=13,880 kg (30,600 lbs)
(travelling)
length=
part_length=45 calibre: 6.97m
(22.86 ft)
width=
height=
diameter=
crew=14
cartridge=
caliber=155 mm (6.1 inch)
action=
rate=40 rounds per hour
velocity=853 m/s (2,800 ft/s)
range=
max_range=23,221 m (25,395 yds)
feed=
sights=
breech=Ashbury breech
recoil=
carriage=M1 Carriage
elevation=−2°/+65°
traverse=60°

The 155 mm Gun M1 and M2 (later M59), widely known as Long Tom, were 155 millimeter calibre field guns used by the United States armed forces during World War II. The Long Tom replaced the Canon de 155 mm GPF in United States service.

Development

Before entering World War I, the United States was poorly equipped with heavy artillery. To address this a number of foreign heavy artillery guns were adopted, including the Canon de 155 mm GPF. After the end of the war development work began in the United States on a design to improve upon the existing models of heavy gun and carriage. A number of prototypes were produced in the 1920s and 1930s, but the projects were put on hold due to lack of funds. In 1938 the 155 mm Gun T4 on Carriage T2 was finally adopted as 155 mm gun M1 on Carriage M1.

The new design used a barrel broadly similar to the earlier 155 mm GPF, but with an Ashbury breech. The new split-trail carriage featured four roadwheels, each mounting two tires. The wheels could be lifted, allowing the gun to rest on a firing platform. This made the gun very stable and thus accurate.

The gun was developed into M1A1 and M2 variants. After the war, the United States Army re-organized, and the gun was redesignated as the M59.

ervice

The Long Tom saw combat for the first time in North African Campaign in 1943, with 34th Field Artillery Battalion. Eventually it equipped about 49 battalions, including 40 in the European Theater and 7 in the Pacific. The preferrable prime mover was initially the Mack NO 6x6 7 1/2 ton truck; from 1943 it was replaced by the tracked M4 High Speed Tractor.Zaloga - "US Field Artillery of World War II", p 20-22.]

A small number of Long Tom guns were supplied via lend lease channels, to the United Kingdom (184) and France (25).Zaloga - "US Field Artillery of World War II", p 37.]

Variants

Gun variants:
* M1920 - prototype.
* T4 - prototype.
* M1 (1938) - first production variant, 20 built.
* M1A1 (1941) - modified breech ring.
** M1A1E1 - prototype with chromium plated bore.
** M1A1E3 - prototype with liquid cooling.
* M2 (1945) - modified breech ring.

Carriage variants:
* T2 - prototype.
* M1 (1938).
* M1A1 - refurbished T2 carriages.

The gun was also mounted on a modified M4 medium tank chassis, in mount M13. The resulting vehicle was initially designated 155 mm Gun Motor Carriage T83 and eventually standardized as 155 mm Gun Motor Carriage M40.Hunnicutt - "Sherman: A History of the American Medium Tank", p 353-355, 570.]

155 mm Gun Motor Carriage T79, based on T23 Medium Tank chassis, never advenced past proposal stage.Hunnicutt - "Pershing, A History of the Medium Tank T20 Series", p 158.]

Ammunition

The gun utilized separate loading, bagged charge ammunition. The propelling charge consisted of base (9.23 kg) and increment (4.69 kg). The data in the table below is for supercharge (base and increment).

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Notes

References

* cite book
last=Bishop
first=Chris
title=Encyclopedia of Weapons of World War II
ISBN=0760710228
* cite book
last = Hunnicutt
first = R. P.
authorlink =
coauthors =
others =
title = Sherman: A History of the American Medium Tank
publisher = Presidio Press
series =
date = 1994
isbn = 0-89141-080-5
* cite book
last = Hunnicutt
first = R. P.
authorlink =
coauthors =
others =
title = Pershing, A History of the Medium Tank T20 Series
publisher = Feist Publications
series =
date = 1996
isbn = 1-112-95450-3
* cite book
last = Zaloga
first = Steven J.
authorlink = Steven Zaloga
coauthors =
others = illustrated by Brian Delf
title = US Field Artillery of World War II
publisher = Osprey Publishing
series = New Vanguard 131
date = 2007
isbn = 978-1-84603-061-1
* cite book
last =
first =
authorlink =
coauthors =
others =
title = Technical Manual TM 9-1901, Artillery Ammunition
publisher = War Department, 1944
series =
date =
isbn =
* cite book
last =
first =
authorlink =
coauthors =
others =
title = Technical Manual TM 9-1904, Ammunition Inspection Guide
publisher = War Department, 1944
series =
date =
isbn =