Medium Tactical Vehicle Replacement

MTVR[1]

MTVR MK23 standard cargo trucks with Armor Protection Kits (APKs) and armored rear troop carrier compartments
Type Family of 6x6 tactical trucks with 7-ton payload (U.S. tons)
Place of origin United States
Service history
In service 2001–present (first fielding 2001)
Used by U.S. Marines and others (see Operators)
Production history
Designer Oshkosh Defense
Designed 1996 (initial development contract)
Manufacturer Oshkosh Defense
Produced 1999–present
Number built 11,350 (est.) U.S. Marines/Navy plus 430 (est.) export sales
Variants

(full details in main text)

  • MK23 - standard cargo truck, 4.674 m wheelbase[2]
  • MK25 - standard cargo truck with winch, 4.674 m wheelbase[2]
  • MK27 - extended cargo truck, 5.486 m wheelbase[3]
  • MK28 - extended cargo truck with winch, 5.486 m wheelbase[3]
  • MK29 - dump truck without winch, 4.674 m wheelbase[4]
  • MK30 - dump truck with winch, 4.674 m wheelbase[4]
  • MK36 - wrecker, 5.486 m wheelbase[5]
  • MK31 - tractor, 4.674 m wheelbase[6]
  • MK28C - replacement for Special Purpose Vehicle types, 5.486 m wheelbase[3]
  • MK37 - HIMARS resupply, 5.486 m wheelbase (based on MK27)[7]
  • MK38 - HIMARS trailer
MK23 standard cargo truck[1][2]
Specifications
Weight 12,610 lbs (curb w/fuel); 14,199 lbs/30,000 lbs (payload off-road/primary & secondary roads)
Length 7.998 m
Width 2.49 m
Height 3.18 m (cab; reducible for transport)
Crew 2
Armor a-kit/b-kit; U.S. Army Long Term Armor Strategy (LTAS) compliant
Engine Caterpillar (CAT) C-12 Advanced Diesel Engine Management (ADEM) III, 11.9-liter, 6-cylinder inline water-cooled diesel developing 425 hp @ 1800 rpm and 2101 Nm torque at 2100 rpm
Payload capacity rated at 7 U.S. tons (off-highway)
Transmission Allison HD 4070P 7-speed automatic and Oshkosh 30000 single-speed with torque proportioning differential and manual differential lock
Suspension Oshkosh TAK-4 independent suspension,[8] coil spring upper/lower control arms; anti-roll bar on second and third axles. Front axle rated at 7,257 kg, second at 10,659 kg, third at 11,567 kg
Fuel capacity 295 litres
Operational
range
 483 km
Speed 105 km/h
Steering
system
 Power-assisted, front axle (third axle contra-steer on MK31 tractor)

The Medium Tactical Vehicle Replacement (MTVR) is a series of vehicles, based on a common chassis that vary by payload and mission requirements. The MTVR is a purpose-designed military vehicle, although a small number of vehicles have been sold commercially for specialized operations such as wildfire fighting.[1][9]

There were originally four MTVR variants, this increasing to seven, and then nine variants (plus a sub-variant) as deliveries and development continued. A dedicated trailer and prototype/developmental MTVRs have also been produced.[1][9]

The first MTVRs were delivered in late 1999. The MTVR is the U.S. Marines’ equivalent of the U.S. Army’s Family of Medium Tactical Vehicles (FMTV). The Marines do not use the FMTV; the Army does not use the MTVR. The MTVR was designed and is manufactured by Oshkosh Defense.[1][9]

Development and production history

The MTVR has its design origins in two U.S. military programs, the 5 ton Tactical Truck Replacement (5TTR) for the U.S. Army, and the Medium Tactical Vehicle Replacement (MTVR) for the U.S. Marines. The aim of these programs was to upgrade and extend the service life of around 3,400 U.S. Army M939 series 5 ton trucks, and 8,100 U.S. Marines M809 and M939 series 5 ton trucks. Prototype and development contracts for both programs were awarded in 1996. The 5TTR program was subsequently halted, and the MTVR program evolved from an upgrade to a new-build requirement.[1]

Oshkosh was awarded a multi-year MTVR production contract in February 1999. The first vehicles were scheduled for delivery by the end of 1999, and deliveries under the initial contract concluded during August 2005. The award initially allowed for up to 8,168 MTVRs (including options for 2,502) in four variants (MK23, MK25, MK27, MK28) to be ordered over five program years; 6,931 MTVRs were delivered, 6,393 to the Marines and 538 to the Navy (Seabees). The first MTVRs were fielded in July 2001. Three additional variants followed, the MK29, MK30 and MK36.[1]

Under a separate contract, Oshkosh commenced production in July 2004 of a further MTVR variant, the MK37. Based on the MK27 and fitted with a rear-mounted Hiab materials handling crane rated at 2,500 kg at 6.1 m maximum reach, the MK37 is a resupply vehicle for the U.S. Marines HIgh Mobility Artillery Rocket System (HIMARS). The companion trailer is designated MK38.[1]

Oshkosh was awarded a second MTVR multi-year contract (FY05-FY10) in July 2004. This award initially covered only potential Foreign Military Sales (FMS), plus the continuing requirements of the U.S. Navy. Ultimately the U.S. Navy and Marines combined received >2,000 vehicles under this contract.[1]

In 2005, the MK31 Medium Equipment Transporter (MET) tractor entered service with Seabees, and later in the year with the Marines.[9]

The MK28C is a variant of the MK28. The MK28C (C - chassis) replaced Special Purpose Vehicle (SPV) types, these based on a mix of tactical and commercial truck chassis and including: water distributor, 2,000 US gallon; fuel, 1,500 US gallon; field service; asphalt distributor; earth auger. Interchangeable commercial-off-the-shelf (COTS) - or modified COTS - bodies are fitted to MK28C chassis as field circumstances dictate.[1]

Also in 2005, Oshkosh was awarded a contract to re-manufacture an initial 27 MTVRs to new configuration and with a full new vehicle warranty.[1]

On 16 May 2008 the 10,000th MTVR was completed. By late 2011 an estimated 11,135 MTVRs had been ordered, that figure including 9,221 for the USMC and 1,855 for the Navy.[1]

In FY12 the third (and current) five-year multi-year MTVR contract was awarded to Oshkosh. The most recent MTVR delivery order (USD67 m for 338 vehicles; 278 Marines, 60 Seabees) was placed in September 2012, and inclusive of this order approximately 11,350 MTVRs have been ordered by the US Marines' to date, about 1900 of these for the Navy. Orders under the current contract can be placed until June 2016.[1][10]

In conjunction with Pierce Manufacturing (an Oshkosh Corporation company), Oshkosh developed the MTVR MK23/25-based Hawk Extreme, a wildland firefighting water tender. This product has been sold commercially.[1]

Technical description

All production versions of the MTVR are based on the same 6×6 drive configuration[11] and utilize a chassis constructed using bolted/huck-bolted formed channel (248 × 76 × 9.7 mm) made of heat-treated carbon manganese steel with a yield strength of 758 MPa. The engine is located under a forward fibreglass hood. The cab seats three and is of welded aluminium extrusion construction with adhesive bonded aluminium skins. The cab folds down to reduce overall height to 2.489 m and from mid-2007, production vehicles are armor-ready and have air-conditioning, revised cab mounts and upgraded cab suspension.[1]

With the exception of the UK's Wheeled Tanker variants, all MTVRs are powered by a Caterpillar C-12, Advanced Diesel Engine Management (ADEM) III 11.9-litre six-cylinder diesel engine that develops 425 hp at 1,800 rpm and 2,101 Nm of torque at 1,200 rpm.[11] When the central tire inflation system (CTIS) is set at 0 to 1,814 kg (2 tons) payload, engine power output is automatically reduced by around 20%.[1] Driveline is completed by an Allison HD 4070P seven-speed automatic transmission, TC-541 torque converter and an Oshkosh 30000 Series single-speed transfer case.[10] All-wheel drive is permanent and under highway driving conditions the torque split is 32% front, 68% rear.

Oshkosh TAK-4 independent coil spring suspension is fitted to the MTVR,[8] this providing each front wheel with a total vertical travel of 406 mm and a travel of 325 mm on the rear axles. The front axle is rated at 7,257 kg, the second at 10,659 kg, the third at 11,567 kg. The MK36 wrecker and MK31 tractor variants have Hendrickson hydraulic suspension on the rear axles.

Standard tires fitted to the MTVR are Michelin 1600 R20 XZL and with the exception of the MK36 wrecker variant, no spare is carried. Compensating for no spare is a runflat setting option on the CTIS. CTIS allows the driver to adjust tyre pressures to suit both payload and terrain conditions, from the driving seat. The two-piece bolt-together steel wheel rims are fitted with beadlocks for extreme low-pressure operations and tires will remain seated at pressures down to 10 psi. In the event that any one tire should fail totally, a limp-home facility allows for a second axle suspension unit to be raised and secured.

Mobility parameters include a climatic operational range of -32 °C (-46 with kits) to +52 °C. The MTVR has a maximum speed of 105 km/h and on-road cruising range of 483 km. It can climb a 60% gradient and traverse a 40% side slope with its maximum cross-country load. It can ford 1.52m of water and surmount a 610 mm vertical step.[10] Turning radius and approach, departure, and ramp breakover angles vary by variant.

MTVR variants can be internally transported by C-5, C-17 and C-130 Hercules transport aircraft. The MK23 can be transported under-slung by CH-53 helicopter.[10]

The original MTVR trailer was designed and developed by Oshkosh to provide a matching trailer for the MTVR truck. Two prototype MTVR trailers were manufactured and tested between May 2000 and March 2001. In June 2005 the U.S. Marine Corps System Command (MARCORSYSCOM) awarded the Choctaw Manufacturing and Developing Corporation (CMDC) a $1.9 million Small Business Sole Source design and development contract for the MTVR Trailer. Oshkosh manufactures and supplies the associated trailers for the MK37 HIMARS resupply variant.[12]

MTVR Armor Systems (MAS)

Oshkosh promotes the current MTVR armor packages as the MTVR Armor Systems (MAS). The current Standard MAS with Survivability Upgrade (MAS-SU) kit is available for a variety of models. The Reducible Height MAS (MAS-RH) is also available. Installation of armor requires a vehicle front axle and cab suspension mount upgrade, plus a revision to the cab roof gun mount. Air-conditioning is also fitted. From mid-2007 all production MTVRs have been armor ready, these modifications now forming part of the standard vehicle specification.[9][13]

Development of a protection kit for the MTVR commenced in 2003, with the first production contract awarded in 2004 and calling for 920 baseline appliqué APKs for the cab, plus 460 modular armored rear troop carrier compartments. The cab and troop carrier kits, while complementary, are separate units and can be installed as such. A follow-on contract for 930 cab kits and 465 rear troop-carrier compartments was awarded in 2005. Two further contracts for a total of 293 cab kits were awarded in 2007. Oshkosh announced in August 2008 an initial contract award for height reducible armor kits for MVTRs. Around 2400 height reducible armor kits for MVTRs have been ordered. Additional awards for armor/protection-related upgrades have been made.[9][13]

A small arms fire and mine blast protection kit for the U.K. MoD's MTVR-fronted Wheeled Tanker fleet has been developed and fitted to vehicles used on overseas operations.[9]

Gallery

Prototype and developmental MTVRs

Operators and details

See also

Bibliography (references and additional reading)

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 "Oshkosh (6 × 6) Medium Tactical Vehicle Replacement (MTVR) and trailers". IHS Jane's. Retrieved 2015-12-23.
  2. 1 2 3 "MK23 and MK25 Standard Cargo Truck (Oshkosh data)". Oshkosh Defense. Retrieved 2015-12-23.
  3. 1 2 3 "MK27 and MK28 Extended Cargo Truck (Oshkosh data)". Oshkosh Defense. Retrieved 2015-12-23.
  4. 1 2 "MK29 and MK30 Dump Truck (Oshkosh data)". Oshkosh Defense. Retrieved 2015-12-23.
  5. ↑ "MK36 Wrecker (Oshkosh data)". Oshkosh Defense. Retrieved 2015-12-23.
  6. ↑ "MK31 Tractor (Oshkosh data)". Oshkosh Defense. Retrieved 2015-12-23.
  7. ↑ "MK37 (Oshkosh data)". Oshkosh Defense. Retrieved 2015-12-23.
  8. 1 2 "Oshkosh MTVR - Military Power". trucktrend.com. Retrieved 2015-12-23.
  9. 1 2 3 4 5 6 7 "Oshkosh MK31 Medium Tactical Vehicle Replacement (MTVR) Medium Equipment Transporter (MET)". IHS Jane's. Retrieved 2015-12-23.
  10. 1 2 3 4 "Oshkosh Medium Tactical Vehicle Replacement (MTVR), United States of America". army-technology.com. Retrieved 2015-12-30.
  11. 1 2 "military-today.com". military-today.com. Retrieved 2015-12-29.
  12. ↑ "Medium Tactical Vehicle Replacement (MTVR) Trailer (MTVR-T)". globalsecurity.org. Retrieved 2015-12-30.
  13. 1 2 "MTVR Armor Protection Kit (APK)MTVR Armor System (MAS)". globalsecurity.org. Retrieved 2015-12-31.
  14. ↑ "MTVR 9-ton LHS". Oshkosh Defense. Retrieved 2015-12-23.
  15. ↑ "MTVR 16.5-ton LHS". Oshkosh Defense. Retrieved 2015-12-23.
  16. ↑ "MTVR 4x4 Short Bed Cargo". Oshkosh Defense. Retrieved 2015-12-23.
  17. ↑ "OsEFP Mines? Ceradyne & i3 Say "Bull!"". DiD. 2007-12-19. Retrieved 2015-12-30.

External links

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