The Turkish variant of the South Korean K9 155mm self-propelled howitzer has been further developed as an NG (New Generation) model. The Turkish T-155 is a 56 ton armored vehicle that uses the South Korean K9 turret, 155mm gun and loading system as well as the K9 engine and some other mechanical elements. This 2001 deal was worth about $1 billion for South Korea, which built the first eight T-155s in South Korea and assisted Turkish firms in setting up facilities to produce the remaining 342. This production order will be completed in a few years and, at that point, Turkey will switch to production of the T-155 NG, which has an upgraded fire control system and an all-electric turret gun control system. External vidcams will enable the crew to view what is going on outside the vehicle. There are also new road wheels and tracks, a new RWS (Remote Weapons Station) atop the turret with a 12.7mm machine-gun and a fire control system for the 155mm gun when used in direct (what the gunner can see) fire mode. The NG also has a new automated ammo handling system for the turret. Turkey recently showed off one of the T-155 NG prototypes but has not announced how many, if any, T-155s would be upgraded to the NG standard or when. The NG model will replace the original one and will probably perform better in the export market. There is only one export customer, Azerbaijan, which purchased 36 in 2011.
Meanwhile, South Korea continues to obtain export sales for its K9 “Thunder” 155mm self-propelled howitzers that the T-155 is based on. In 2018 Estonia ordered 12 and Egypt is evaluating the K9 and expected to order in 2019. In 2017 Norway ordered 24 K9s. That $215 million order includes six K10 armored resupply vehicles, tech support, some spares and an option to buy 24 more K9s on the same terms. The first K9s arrive in 2019 and will replace Cold War era U.S. M109A3 vehicles.
In 2017 Finland ordered 48 used (by South Korea) K9s. The largest recent K9 sale was to India, but that one came with a catch. In 2016 South Korea agreed to partner with an Indian firm (L&T) to build a hundred K9s for the Indian Army. The K9s will cost about $7 million each and half the work will be done in South Korea while the rest will be done in India by L&T. The Indian Army wanted 250 K-9s but budget problems limit the current deal to 100. South Korea also made deals to provide major components of the K9 (mainly the chassis) to Poland (as they did with Turkey) so they could build a local self-propelled howitzer around it.
The K9 entered service in 1999 and the South Korean military has ordered over 1,100 since then and is even replacing some of the earlier ones with newly manufactured ones. South Korea also bought 179 of the K10 ammunition resupply vehicles.
While superficially similar to the American M109 the K9 is heaver (46 tons versus 28 for the M109), carries more ammo and has twice the range (up to 56 kilometers in part because of a barrel that is a third longer). There is more automation on the K9, so it has a crew of five versus six on the M-109. With the K9, South Korea joins Germany in their effort to build a suitable replacement for the elderly M109 design. The chief competitor for the Indian contract was Russia which offered its similar 42 ton 2S19. The K9 won on the basis of technical capabilities, field tests and a South Korean reputation for quality and reliability.
This is all the result of South Korea deciding to become a major weapons developer and exporter. This began in the 1990s after South Korea had become a major economic power and exporter. South Korea has been successful at this although the largest customer remains the South Korean military, which has to deal with the threat from North Korea.
Despite the success of the K9 and T-155, the future of self-propelled 155mm artillery is not bright. The United States sought to build a replacement for the M-109 (the 56 ton Crusader) that was very similar to the K9 but was too complex and expensive and the heavier weight was seen as a disadvantage for a country that has to ship its armored vehicles overseas to use them. For South Korea, Turkey and Poland that is not a problem and more heft (and protection for the crew) is an advantage. Turkey encountered this recently as it used its T-155s to fight Islamic terrorists in Syria and Kurdish separatists in eastern Turkey and northern Iraq. In all these situation the irregular forces the T-155 was firing on used ambush and explosives to attack road traffic and the heavily protected T-155 was less vulnerable to this threat.
One American innovation that reduced the demand for 155mm artillery in general was the GPS guided Excalibur shell. This smart shell entered service in 2008 and changed everything. Excalibur has worked very well in combat, and this is radically changing the way artillery operates. Excalibur means 80-90 percent less ammo has to be fired to destroy a target, and this results in less wear and tear on SP artillery, less time needed for maintenance, and less time spent replenishing ammo supplies and more time being ready for action.
Because of Excalibur (and other precision munitions) since 2001, operations in Iraq and Afghanistan provided very little work for the M-109. The lighter, towed, M777 has proved more useful, especially when using the Excalibur shell. Currently, the army plans to keep newly upgraded versions of the M-109 around until 2050. The army plans to acquire at least 551 upgraded M-109s by 2027, reflecting the impact of the Excalibur shell, and the number of older M-109s that are still fit for service. The M-109 was a solid design, which is pretty clear from how difficult it's been to come up with a replacement. So, in the end, the army replaced the M-109 with another M-109 upgrade and is still seeking a replacement for that. For many nations, the heavier self-propelled 155mm howitzers are no longer an attractive purchase because of the GPS guided artillery and rockets.