US 280mm Atomic Cannon fired at Frenchman's Flats Nevada Test Center in 1953.

>>20196
In case anyone cares, the M65 that fired this test shot is on display at Ft. Sill, OK.

Test shot was Operation Upshot-Knothole, Grable shot. The only artillery-fired atomic weapon ever used. W9 warhead, gun-type assembly making use of enriched uranium. Test shot rated at 15kt, roughly 1 kt more than Little Boy at Hiroshima.

Fun fact: gun type warheads are extremely inefficient but almost guaranteed to detonate. A "successful" detonation only fissions 1-2% of the total critical mass, as prompt criticality kicks in and detonates the two slugs before they can fully close the distance and merge (actually when they were about 9" apart still in the case of Little Boy). If Little Boy is still anything to go by for gun-types, the W9 hit 15KT yield from 1-2% fission of 110+ pounds of uranium for fuel. 1.5 mol of U-235 is needed to initiate super-criticality. 1 mol is a little over 100 pounds. So assuming an improved shot speed forcing the two slugs together faster than prompt criticality requires, from higher velocity high-explosive initiators, given a 2% efficiency only 2-3 pounds of uranium actually explodes in the W9 warhead and the rest is vaporized and coverts to plasma in the heat of the detonation.

Hey, guys, what is currently the most modern US self-propelled artillery? And what kind of gun does it have, rifled or smoothbore?

>>20219
It looks like the Paladin (first fielded in 1962) SPH is the latest with the M109A7 upgrade. The XM2001 Crusader and XM1203 Non-Line-of-Sight Cannon were cancelled.

The XM2001 Crusader was to be the United States Army's next-generation self-propelled howitzer (SPH), designed to improve the survivability, lethality, mobility, and effectiveness of the artillery as well as the overall force. It was initially scheduled for fielding by 2008. United Defense was the prime contractor; General Dynamics the major subcontractor. In early May 2002, Secretary of Defense Donald Rumsfeld cancelled the $11 billion USD program because he considered it neither mobile nor precise enough. https://en.wikipedia.org/wiki/XM2001_Crusader

More Crusader stuff here:
http://www.operatorchan.org/k/res/91469.html
The XM1203 Non-Line-of-Sight Cannon (NLOS Cannon) was a mobile 155 mm cannon intended to provide improved responsiveness and lethality to the "unit of action" (UA) commander as part of the US Army's Future Combat Systems project. This self-propelled armored artillery piece provided networked, extended-range targeting, and precision attack of point and area targets in support of other combat units with a suite of munitions that include special purpose capabilities. The Non-Line-of-Sight Cannon provided sustained fire for close support and destructive fire for tactical standoff engagement. The NLOS Cannon used technology from the canceled XM2001 Crusader.

NLOS-C was a proposed system in development to be part of the FCS environment and funded by the U.S. Congress shortly after cancellation of the XM2001 Crusader M109 replacement. It was an 18-ton class vehicle that would have been a replacement for current vehicle systems in the 40-60 ton weight class. It would provide a level of air transportability that current M109 systems cannot at present match. https://en.wikipedia.org/wiki/Future_Combat_Systems_Manned_Ground_Vehicles#Non-line-of-sight_cannon

The CAESAR from CAmion Equipé d'un Système d'ARtillerie (French: Truck equipped with an artillery system) is a 155 mm/52-calibre gun-howitzer installed on a 6X6 truck chassis. Examples built for the French Army use a Renault Sherpa 10 chassis, examples built for export utilize the 6x6 Unimog U2450L chassis. The CAESAR platform was developed by the former GIAT Industries (now known as Nexter) and is operated by the French, Indonesian, Saudi Arabian, and Thai militaries. https://en.wikipedia.org/wiki/CAESAR_self-propelled_howitzer

The CAESAR is a wheeled, 155mm 52-caliber self-propelled howitzer. It holds 18 rounds and is typically operated by a crew of five, though if necessary, the CAESAR can be operated by as few as three men. It can be transported by C-130 or A400M, and has a firing range of approximately 42 km using an Extended Range, Full Bore (ERFB) shell, and more than 50 km using rocket assisted shells. The system is integrated with a fully computerized system, providing an automatic control. During Eurosatory 2006, CAESAR was exhibited with an automated laying system based on the SIGMA 30 inertial navigation system.

Nexter is developing an armored cab for the CAESAR in response to demand for more protection for the crew. The additional armor will protect against IEDs and roadside bombs, anti-vehicle mines, and 155 mm shells landing as close as five meters (16 feet) away from the vehicle. It can be added to the cabs of existing CAESARs. Heavier armor will increase its weight by 400 kg (880 pounds) and raise the price by 4-5 percent.

- French soldiers conduct a live-fire exercise, with their Nexter Systems Caesar self-propelled wheeled armored vehicles, outside of Bagram Airfield, Afghanistan, August 14, 2009.

French soldiers conduct a live-fire exercise, with their Nexter Systems Caesar self-propelled wheeled armored vehicles, outside of Bagram Airfield, Afghanistan, Aug. 14, 2009.

>>20224
The main chassis of the NLOS-C was based on the Manned Ground Vehicle (MGV) platform being developed for all manned ground platforms under the Future Combat Systems Program, giving the NLOS-C a high commonality with other MGV-based platforms, especially the NLOS-M (Non-Line-of-Sight Mortar). Use of a common chassis was to reduce the need for specialized training of personnel and allow for faster fielding of repairs. The MGV platform utilized a hybrid diesel-electric propulsion system. The MGV also employed numerous weight-saving features, including composite armor, composite and titanium structural elements, and continuous band tracks.

U.S. Senator Jim Inhofe and Chief of Staff of the Army Gen. George W. Casey, Jr. traveled to BAE Systems in Minneapolis, Minnesota in late May 2008 for the rollout of the first Non-Line-of-Sight Cannon prototype. Prototype 1 made its first public appearance on the National Mall in Washington on June 11, 2008. A total of eight prototypes were delivered to the U.S. Army Yuma Proving Ground, Arizona, by 2009.[12] The program was officially cancelled in 2009, along with the rest of FCS.

The earlier test vehicles of the NLOS-C appeared to mount a 155mm M777 Light Towed Howitzer on a light tracked chassis. The tow hitch was even not removed from the muzzle.

Proving this 155mm howitzer is actually lightweight, here's some Marines shoving one around.

The M777 is smaller and 42% lighter, at under 4,100 kg (9,000 lb), than the M198 it replaces. Most of the weight reduction is due to the use of titanium. The lighter weight and smaller size allows the M777 to be transported by the MV-22 Osprey, CH-47 helicopter or trucks with ease to provide increased mobility and more compact storage over the M198. The minimal gun crew required is five, compared to a previous nine. https://en.wikipedia.org/wiki/M777_howitzer

- Marines with Battalion Landing Team 3/8, 26th Marine Expeditionary Unit, move a M777 Lightweight Howitzer into place on the flight deck of USS Carter Hall at the Morehead City Port, N.C., August 28, 2010. 26th Marine Expeditionary Unit deployed aboard the ships of Kearsarge Amphibious Ready Group in late August responding to an order by the Secretary of Defense to support Pakistan flood relief efforts.

Here the US 155mm XM1203 Non-Line-of-Sight Cannon (NLOS-C) prototype has a different muzzle brake and an armored box around the recoil works and a turret around the breech.

One design concept I read about had an attached ammo vehicle that would automatically replenish the howitzer.

SGT Antonio Hinojosa, A Battery, 2nd Battalion, 3rd Field Artillery, 1st Armored Division Artillery, Fort Bliss, Texas, waits to give the command to his team to fire their M777A2 howitzer during the Iron Strike exercise.

Soldiers from the 2nd Battalion, 3rd Field Artillery, Gunner Battalion, provide direct support Fires to the 1st Brigade Combat Team (Stryker) (BCT), 1st Armored Division (AD). Following its redeployment from Afghanistan in the fall 2013, the battalion supported a variety of division missions, including providing two batteries to train Regional Officers' Training Corps (ROTC) cadets during their summer training at Fort Knox, Ky. With the return of all batteries in August 2014, the Gunners began certifying M777A2s howitzer sections and fire direction centers and supporting the 1 BCT's live-fire exercises. Some of the most dynamic training included the battalion’s first air assault artillery raids with sling loaded M777s under CH-47 Chinook helicopters, and Fires in support of joint exercises with Forward Air Controller-Air (FAC-A) pilots calling for fire from A-10 Warthogs.
With the reconstitution of the DIVARTY, the Gunner Battalion expanded to include the 1 BCT fire supporters and their Stryker-variant fire support vehicles. Now when a battery deploys for training, they have a habitual relationship with both a fire support element and an Infantry battalion. The Gunners are now focused on the train-up for their June 2015 rotation to the National Training Center (NTC), Fort Irwin, Calif., with 1 BCT and assumption of the regionally aligned force (RAF) mission in support of U.S. Northern Command (NORTHCOM). http://sill-www.army.mil/firesbulletin/2015/jan-feb/activefa.html

>>20220
What's the bore on those cannons though? Rifled or smooth?

>>20239
IIRC, M109s use rifled barrels.

>>20239
Sources don't say if the Crusader uses a rifled or smoothbore barrel (default assumption would be rifled).
http://fas.org:8080/man/dod-101/sys/land/crusader.htm

- Here you can see the rifling inside the barrel of this US 155mm M777 Light Towed Howitzer.

>Non-Line-of-Sight Cannon
>Non-Line-of-Sight Mortar
Isn't all artillery non line of sight?

>>20242
They were so-named because they were beyond-the-horizon capable systems with advanced RAP in the NLOS-C and a full array of external powder charges in addition to the regular booster propellant rings and a proposed glide-capable GPS-guided mortar munition in the NLOS-M.

Before cancellation NLOS-C, from the completed demonstrator unit, was posting 22-mile ranges without RAP in test shots. However accuracy wasn't significantly increased over M-109 without GPS guidance, and there were issues getting the full weight of the system down and deployment ranges up.

>>20241
Wow, that's some steep rifling. Reminds me of microgroove.

>>20239
Smoothbores would need fins for stabilization.

>>20242
Marketing and no other reason. Remember these projects came along during the terrorist money glut, and were mostly designed to sap as much money as possible before getting cancelled.

>>20243
>22 mile
Is normal for 155mm artillery. Most such guns hover around 23 miles clean, around 27 miles with base bleed or various ballistic coefficient tricks, and 37 miles with rocket assist.

>>20245
Oh, yeah, I wasn't saying it was stellar. That's part of the reason it was canceled; they were claiming well beyond that without RAP from a short-caliber cannon and weren't delivering while also being unable to shed weight and increase range, all the while no one could get ammo developed that would meet the range goals. IIRC, one of the original RFPs from the designer of the NLOS-C demonstrator claimed that once all R&D was done 30-50 mile ranges without RAP could be achieved. ( I believe BAE was the cannon's designer, not sure about the chassis.)

Why waste the money on another gimped "law of averages" type universal system?

The PLZ05, also referred as the Type 05, is a recent Chinese development. It was developed as a successor to the Type 83 SPH. It evolved from the PLZ45.
This 155-mm self-propelled howitzer has an automatic ammunition loading system. Some sources report, that this autoloader has been copied from the Russian 2S19 Msta-S.
The PLZ05 fires Chinese 155-mm ammunition. Maximum range of fire with rocket-assisted projectile is over 40 km. It is also capable of firing precision-guided projectiles with a maximum range of 20 km. It is worth noting that in the 1990s China obtained the Russian Krasnopol laser-guided projectile technology. Later China successfully developed its own precision guided munitions. Also there is a GPS-guided projectile with a claimed maximum range of 100 km, however it is unconfirmed.
Maximum rate of fire is about 8 to 10 rounds per minute. Onboard ammunition supply is around 30 rounds.
This self-propelled howitzer is supported by an associated ammunition resupply vehicle, which carries ammunition under armor on the battlefield. The resupply vehicle carries about 90 rounds and is capable of automated delivery. This support vehicle is fitted with a crane, which is used for ammunition handling operations and can be also used to replace the powerpack and for other load-handling operations. http://www.military-today.com/artillery/top_10_self_propelled_howitzers.htm

PLZ-05 / Type 05: Self-propelled howitzer with a 52 caliber barrel, 800 hp diesel engine & gross weight of 35 tonnes. It is deployed only with the People's Liberation Army. The PLZ-05 can fire the WS-35 shell, a 40 lb (18 kg) guided munition with accuracy of 40 m (130 ft) and a max range reported to be 100 km (62 mi). It is guided using Beidou Navigation Satellite System, the Chinese version of global positioning system, and inertial guidance.

PLZ-52: The PLZ-52 is a 155mm / 52 caliber tracked self-propelled howitzer similar in appearance to the PLZ-45, but based on a slightly different hull. Having a gross vehicle weight of 43 tonnes, the PLZ-52 features a new powerpack, which consists of a diesel engine developing 1,000 hp at 2,300 rpm coupled to a fully automatic transmission. This gives a maximum road speed of up to 65 km/h and an operational range up to 450 km. The PLZ-52 howitzer has a maximum firing range of 53 km (with ERFB-BB-RA projectiles), maximum firing rate of eight rounds per minute, a burst firing rate of three rounds per fifteen seconds, and a multiple-round simultaneous impact capability of four rounds.

The driver and powerpack are at the front of the hull with a fully enclosed turret at the rear. It has torsion bar suspension with six dual rubber tyred road wheels, a drive sprocket at the front, idler at the rear and track return rollers. The PLZ-52 is offered for export.

PLZ-04: Self-propelled howitzer with a 54 caliber barrel and apparently offered for export.

Chinese 155mm PLZ-45 reportedly has a 53 km range using a pictured rocket assisted shell.

>>20091
The Panzerhaubitze 2000 ("armoured howitzer 2000"), abbreviated PzH 2000, is a German 155 mm self-propelled howitzer developed by Krauss-Maffei Wegmann (KMW) and Rheinmetall for the German Army. The PzH 2000 is one of the most powerful conventional artillery systems deployed in the 2010s. It is particularly notable for a very high rate of fire; in burst mode it can fire three rounds in 9 seconds, ten rounds in 56 seconds, and can—depending on barrel heating—fire between 10 and 13 rounds per minute continuously. The PzH 2000 has automatic support for up to 5 rounds of Multiple Rounds Simultaneous Impact (MRSI). The replenishment of shells is automated. Two operators can load 60 shells and propelling charges in less than 12 minutes. PzH 2000 has also been selected by the armies of Italy, Netherlands, Greece, Lithuania and Croatia, and more orders are probable as many NATO forces replace their M109 howitzers. https://en.wikipedia.org/wiki/Panzerhaubitze_2000

- A Howitzer 2000 tank from the Netherlands is fastened to the floor of a C-17 Globemaster III aircraft at Ramstein Air Base, Germany, Sept. 6, 2006. The C-17, from the Charleston Air Force Base, S.C., is transporting the 60-ton tank to Afghanistan.

Although not the latest SPH, the German PzH 2000 is often regarded as the best.
What SPH would you consider the best?
Rate by rounds per minute, shell range, accuracy, chassis speed, air-mobility, ammo replenishment speed?

An Italian Army PzH 2000, self-propelled Howitzer on October 17, 2015 during Trident Juncture 15.

>>20247
Interesting to see the Chinese made this in 155mm and not the Soviet 152mm.

US 203mm (8-inch) M110 self-propelled howitzer in Vietnam.

US 203mm M110A2 8-inch self-propelled howitzer.

- US WW2 203mm (8-inch) M115 towed howitzer.
The M115 203 mm howitzer, also known as the M115 8 inch howitzer, was a towed howitzer developed and used by the United States Army. Until the 1950s it was designated the 8 inch Howitzer M1. The original design started in 1919 but lapsed until resurrected in 1927 as a partner-piece for a new 155 mm gun. It was standardised as 8 inch Howitzer M1 in 1940. The M115/M1 was towed by the M35 Prime Mover gun tractor or a Mack 7 1⁄3 ton 6x6 truck.

Like the British BL 8 inch Howitzer of the First World War, the M115 uses a Welin screw for its breech. The carriage was the same as used for the US 155 mm gun and was also adopted by the British for their 7.2 inch Mark 6 howitzer. It consists of equilibrator assemblies, elevating and traversing mechanisms, two single-wheel, single-axle heavy limber, two-axle bogie with eight tyres and two trails. Four spades, carried on the trails, are used to emplace the weapon. The British 8 inch howitzer was produced in England and under license in the US, for the American Expeditionary Forces in Europe during World War I, as the 8-inch Howitzer MK. VI. It was in service with the US Army till replaced by the M115. There are no reports of the MK. VI or another marks being used during World War II.

The first photos of the M115 type 8 inch cannon on its redesign carriage appeared in 1931 but development was slowed by the Great Depression.

The M115 saw U.S. service in World War II, the Korean War, and the Vietnam War. In the late 1950s, it was adopted in small numbers by several NATO armies, to fire the W33 (M454 shell) and later the W79 nuclear artillery shell, under the NATO nuclear sharing concept, a role which ended when the smallest types of tactical nuclear weapons were removed from service and eliminated. It was also adopted as a field weapon by a number of nations in Europe, the Middle East, and Asia and saw service in the Second Taiwan Strait Crisis and the Croatian War of Independence.

UK WW1 8-inch (203mm) BL Howitzer Mk 6 in Russia.

UK WW1 8-inch BL Howitzer Mk 6, aka US Model 1917, supplied to the Finnish army.

UK WW1 8-inch BL Howitzer Mk 8 at the Canadian War Museum in Ottawa.