GC-45 howitzer: Encyclopedia II - GC-45 howitzer - Design History

GC-45 howitzer - Design History

The general design follows several decades of work by Bull with fin-stabilized artillery shells, starting at CARDE and later at Project HARP. In these projects accuracy was not a huge concern, the objective was muzzle velocity, and the test articles were finned darts representing missiles. Yet with the removal of the rifling and the soft-metal driving band on the shell itself, the shell could be designed purely for ballistics, as opposed to having the external constraint of the driving band being located near the balance point of the shell. A system combining some sort of rifling for accuracy without a driving band would result in a much longer ranged weapon.

After years of research at his Quebec firing range, Bull eventually settled on a solution. Instead of conventional rifling where the shell rides on raised "lands", his design effectively used "reversed rifling", grooves cut into the barrel. The shell rode the rifling via small "fins", and had no soft-metal area where the propellant could "blow by" the shell, allowing much more powerful propellants to be used. The resulting Extended Range, Full Bore (ERFB) ammunition was key to SRC's designs, a "pointy" looking shell that carried more explosive than conventional designs, had much lower drag at supersonic speeds, and was more accurate. For longer range applications he added a base bleed system, as well as an even longer-ranged system with a rocket booster.

Now all that was needed was the weapon to fire it. Using the U.S.-standard 155 mm (6 inch) M109 howitzer as the basis of his experiments, the GC-45 was developed by boring out the barrel to a smoothbore, cutting the new rifling into it, and welding an extender onto the end. The result was a longer 45-caliber weapon in place of the original 39-caliber M109, and when used with "zone 11" propellants (as opposed to "zone 7" for the M109) could place the base-bled rounds at 39,000 m with the same accuracy as the M109 at its maximum range of 18,200 m. At shorter ranges the GC-45 could easily repeatedly place rounds into 10 m circles, and could be used in the direct fire role to about 3,000 m.

Bull's work was funded indirectly by the CIA, who put him in touch with (what is today) Denel in South Africa. At the time there was an arms embargo in place, but everyone involved in both the U.S. and Canadian governments looked the other way. Denel designed a new mounting to replace the U.S. version that was able to handle the increased recoil, on top of a four-wheel chassis. The chassis was powered by a small Diesel engine acting as an APU, driving hydraulics that could set up the gun in two minutes, and move it short distances. The change of administration and increasing animosity towards South Africa eventually ended the protection that Bull had, and in 1980 he was brought up on charges of illegal arms dealing. After pleading guilty he was imprisoned in the U.S. for six months.

Denel continued development of the weapon, now basically finished, and it was put into service use in South African in 1982 as the G5. These saw service against Cuban and FRELIMO forces in the Angolan conflict, where they soon wiped out FRELIMO artillery in the border areas. With highly accurate artillery pouring down far behind the front lines, any offensive actions were impossible, and led directly to the ending of active hostilities.

The G5 was also sold to Iraq, who had been on the wrong end of artillery exchanges during the early days of the Iran-Iraq War, and wanted a new weapon that would completely outrange the older U.S. designs in Iranian service. Some were also sold to Israel, who mounted them on Centurion tank chassis to form the M-77, some of which saw service in Bekaa Valley in 1986. When Saddam Hussein learned of this he was incensed, and refused further shipments from Denel.

By this point Bull had been released from prison, and left Canada to set up shop in the arms-dealing capital of the world, Brussels. Here he offered his services to anyone with money, and was soon contacted by both China and Iraq. Bull set up a deal with NORICUM in Austria to produce a new-build version of the GC-45 as the GHN-45. The first foreign sales were eighteen with ammunition which were sold to the Royal Thai Navy for use by their Marine Corps.

Deliveries soon started to Iraq as well, where they had a similar effect on the ongoing Iran-Iraq War as the G5 had in Angola, stopping any push by the Iranians deeper into Iraq. During the Gulf War, however, the GHN-45s proved less effective than anticipated by either side. Air strikes had disrupted the Iraqi command and control facilities, and because most of their gun tractors had been withdrawn to serve with logistics units in a attempt to re-supply the front line troops, they were unable to withdraw when under fire. Immobile and unsupported the majority of the guns were destroyed at their positions either by air strikes or Multiple Launch Rocket Systems (MLRS) counter-battery fire.

The Chinese armed forces also used the NORICUM version, producing it as the Type 89 starting in 1986. They also mounted it on a locally-designed tracked chassis to produce the PLZ-45 (also known as the Type 88), along with a ammo-carrier based on the same chassis. Interestingly the PLZ-45 did not enter service with the PLA due to costs, primarily because their existing artillery was all based on Soviet-standard 152 mm ammunition. However two major batches of PLZ-45's were sold to the Kuwaiti Army in 1997 and 2001.

The Denel G5 version has also seen continued development. The gun has been placed on an OMC 6x6 chassis as the G6 howitzer, and won major export sales to the United Arab Emirates and Oman. In response to an Indian requirement, the G5 was mounted on a 4x4 truck, resulting in the T5, though as yet no orders for this variant have been forthcoming. It is also fitted into a turret that can fit on any suitable vehicle. The turret is marketed as the T6 which has already being fitted on the T-72. Denel also used the basic ERFB ammunition concept to develop a new 105mm gun, the G7 howitzer, which has become more interesting as forces look to downsize their artillery to improve mobility.

The dominant artillery system in the "Western World" remains the U.S. 155/39 as used in the M109. When it was first introduced the ERFB concept was rejected for NATO service, but a slower post-Cold War upgrade series led to it being re-evaluated when new purchases started in the mid to late 1990s. An even longer 52-calibre version of the basic GC-45 system appears to be becoming a de facto standard for these newer designs, and most examples with the exception of the Chinese have moved to this larger gun (for instance, the G5-2000). With ranges of up to 47,500 m, Bull's basic design now dominates all future artillery systems.

Adapted from the Wikipedia article "Design History", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki