The Howtar

The "HOWTAR"

A Brief History:
During the early 1960's, the United States Marine Corps was looking to improve on and to consolidate their tactical requirements for Close Support Artillery. They also had the requirement to be a more mobile force with the new tactical air-mobility concept of vertical assaults that was fast becoming Marine Corps doctrine.

With the Marines still having the very popular 75-mm Pack Howitzer of WWII fame as well as the fairly new M30 4.2-Inch (107-mm) mortar in their inventory, it was decided to see if the concept of mating the 4.2-Inch tube to the Howitzer's carriage would actually fit into this new requirement.

With various modifications to the howitzer's M3A3 (?) carriage, and the installation of the M99 Cannon in place of the 75-mm howitzer to this carriage, this combination became known as the Model 98 HOWTAR. Trials of the HOWTAR proved out to be successful and it was officially accepted into USMC inventory in May of 1962. A battery of six guns would be assigned to each direct support artillery battalion in exchange for the 'traditional' and labor intensive M30 mortar.

Transporting the HOWTAR was accomplished by sling load from helicopters (H-34, CH-46, CH-53), pulled by 1/4 or 3/4 ton vehicles or could be disassembled to be carried by individual Marines. The ease of transporting the HOWTAR would prove to be invaluable during the 1960's.

Rivaling the 105-mm M101 Howitzer in destructive power, and approximately one-half of the weight, the HOWTAR fired the slightly larger 107-mm (4.2") standard range of munitions. Range capabilities were greater for the 105-mm but, for the CSA work as originally intended for the Model 98, long range was not a necessity. The HOWTAR was intended to fire its rounds at a much higher angle.

Initially deployed with the Marines during the Dominican Republic Crisis of 1965 and would also go on to serve with distinction during the Vietnam War, often operating in conjunction with the M30 4.2-Inch mortar. However, the HOWTAR's service life would be relatively short and by the end of the 1960's, it would be phased out of front-line service, only to be replaced by the M30 mortar that the HOWTAR was originally destined to replace. The HOWTAR would finish out it's final days in Marine Corps inventory as a ceremonial gun firing blank rounds and at least one is known to have been restored. This restoration now resides at the Marine Corps Museum, Quantico, Virginia.

The Model:
This1/35th scale subject is constructed from various items as there are no model kits available of the Model 98. The basis for this subject being the Roy Models 75-mm Pack Howitzer, which was heavily modified, Evergreen and Plastruct strips, rod and tubing as well as fine gauge brass wire. The sighting unit is from a Tamiya M30.

The Roy Models 75-mm howitzer is very nicely cast in a fragile light tan resin and is a very close match to the Tamiya cast white metal 75-mm Pack Howitzer that is being shown on this page for comparison. There was some slight warping of a couple of the resin parts but, this was easily fixed with warm tap water and a gentle hand bending.

My only issues with the Roy Models kit (as well as was with the Tamiya kit) are the axle and wheels. For some reason, the axle is offset from the gun's centerline... enough to make it an unstable towing platform in my opinion. I was not able to verify this offset anywhere during my research on the HOWTAR or as well as on the 75-mm Pack Howitzer so, I modified the axle length to eliminate this offset and also to bring the model to the proper width. The tire tread could also have been a little more defined.

There were a few air bubble pockets encountered that needed to be filled and some minor parting line removal was required. Super glue was used in the construction of this subject.

This conversion was not very difficult to make. There is a good amount of 'surgery' to be performed to the resin parts and once this is done, the conversion part assembly goes along quite rapidly. Very limited reference for the Model 98 is available on the internet and what is available is not all that clear however, I was extremely fortunate to have had a copy of one of the Tech Manuals (TM) set to me (shown below) and this was an invaluable help in the detailed construction of this subject as well as providing the actual statistics.

Comparison: Tamiya's model of the 1/35th scale cast metal 75-mm Pack Howitzer, identical to the Roy Models resin version being used for this HOWTAR conversion. (Model built: January 1986)

Unfortunately, both the Roy Models resin and the Tamiya white metal models of the 75-mm Pack Howitzer are now currently out of production and are difficult to find. I was able to obtain the resin offering via the internet.

The Extras:
	The M14 rifle is from the Dragon Vietnam War Weapons Series. The sling and 'hardware' were constructed out of lead foil and scrap photo-etched brass bits.

	The M329 HE rounds are from the Tamiya M30 kit. These were updated to better reflect the actual Cartridge Container Extensions and Propellant Increment Bundles. (For detailed ammo information, refer to the M30 page.)

	The resin ammo crates are from Armand Bayardi and are beautifully cast and are as purchased. My only remark about these crates is that it would have been better if the crates were all stacked the same way... i.e.: being 'opened' from the same side.

The sandbags are made from Marblex self-hardening clay and sewing thread.

The Figures:
The two Marines are from Hobby Fan. They are superbly cast in resin and require only the removal of the resin pour plugs and some light spot sanding. There were also very few air bubble pockets found and these were filled with a dap of super glue. The only modifications were to replace the arms from my spare arms drawer as the original poses were not applicable to this vignette.

They wear the jungle uniform of the mid to later 1960's Southeast Asia issue with M1955 body armor, M1956 web gear including metal canteens and M1 Helmets. My only complaint is that the helmets have the camouflage cover bands molded on and the Marines were generally not issued this item.

The "US" decals on the canteen covers etc are wet-transfers from Hudson and Allen.

The Base and Groundwork:
The base is scrap pine wood, 3/4 inch thick and is cut to 5 inches in diameter. It is stained with an oil based natural colored stain and then sealed with multiple coats of polyurethane, lightly sanding in between coats. The wood was then masked off with low-tack drafting tape in preparation for the groundwork and paint being applied.

The groundwork is a mix of Sculptamold and wood glue spread evenly and prior to this setting up, the footprints, tire and trail ruts and the locations of the ammo crates were pressed in. Once the groundwork was dry, very fine sand/dirt was sprinkled about and in places. This being secured in place with a water diluted white glue mix.

The nameplate was made on my computer and is fastened to the wood base with double-sided tape.

Painting, Weathering and Finishing:
Paint preparation consisted of soaking all sub-assemblies in a warm water and dish detergent solution for a few minutes and left out to thoroughly dry. The entire subject was primed with a gray acrylic primer with all subsequent painting being done in acrylics as well. Various washes applied were created from a mix of artist oils and "Terponoid" odorless brush cleaner. Various oil colors being used. Dry-brushing was accomplished again with acrylics in various colors. Earth tone pastel chalks from Bragdon Enterprises were used for the final weathering effects. The final step to this completing this vignette was to lightly over spray with an acrylic flat coat.

Model 98 General Description:
The towed 107-mm mortar, M98 is a mobile artillery piece. It is manually operated and drop fired. The recoil mechanism is hydropneumatic type, having a floating piston and an adjustable pneumatic respirator. The mortar is used for indirect fire and can be elevated to high angles to deliver plunging fire on target.

This weapon is composed of the 107-mm mortar cannon M99 with recoil mechanism M38 mounted on carriage M33.

Tabulated Data:
A. Data pertaining to 107-mm Mortar Cannon M99:	B. Data pertaining to 107-mm Mortar Carriage M33:
1) General: Caliber: 107-mm (4.2-Inch) Length (tube and base cap): 70-15/16 in. Weight (tube and base cap): 245 lb. Rifling: 24 Lands and Grooves, graduated right-hand twist. Range (Maximum): 5,500 m (6,015 yd.) 2) Performance (average for new mortar): Type of ammunition: Fused and semi-fixed, complete round. Weight of projectile (approximate): 25 lb. Method of loading: Hand. 3) Sight Unit: M-34A2 M-79 Sight Mount XM-7 M-9A1 Adapter. M-62A/C Elbow Telescope. M-45 Boresight.	Type: Modified box type. Wheels: Automotive type, high speed. Tire size and type: 6.00 x 16 standard. Tire pressure: 20 lb. Weight of each wheel with tire: 90 lb. Brakes: None. Limits of elevation: Maximum: 1007 mils. Minimum: 117 mils. Traverse: Type: Axle. Maximum right: 63 mils. Maximum left: 63 mils. Equilibrator: Type (contained in trail): Spring (2).
C. Data pertaining to 107-mm Mortar Recoil Mechanism M38:	D. Data pertaining to Overall Dimensions of Mortar and Carriage:
Type: Hydro pneumatic. Maximum recoil allowable: 32 in. Minimum recoil allowable: 25 in. Normal recoil: 27 to 31 in. Nitrogen pressure at 70° F: 1,500 psi. Recoil oil: Type: Petroleum base hydraulic oil. Capacity: 3 pt. Reserve in recuperator: 1/2 fill of oil filling gun.	Length: 133 in. Width: 50 in. Height: 51-1/4 in. Road clearance: 9-7/8 in. Weight complete: 1289 lb.



TM 04051A-35/2 September 1963 Author's collection via Mr. Jerrill F. Janik

The M14 Rifle: Caliber: 7.62x51 mm NATO (.308 Winchester). Action: Gas operated, rotating bolt. Length: 1120 mm (44.1 in.) Barrel Length: 559 mm (22 in.) Weight Loaded: 5.1 kg (11.24 lb.) Weight Empty: 8.7 lbs.(3.95 kg.) Weight of full magazine and sling: 11.0 lb. (5.0 kg.) Magazine: 20 rd., detachable box. Rate of fire: 700-750 rpm. Range: 600 yd. (539 m.) Maximum effective range: 500 yd. (457 m.) M14 Muzzle velocity: 2,800 ft. (853 m.) per second. Ammunition types: M59: Ball M61: Armor Piercing M62: Tracer M63: Dummy M64: Grenade Cartridge M80: Ball M82: Blank M118: Special Ball (Long range) M276: Dim Tracer

	Dept of the Army TM scans courtesy of Mr. Dave Craft (Wanted: USMC M14 Manual cover scans!)

The M14 Rifle as well as the M24 Sniper Rifle variation are still in use today, having been deployed in limited numbers throughout the War on Terror.

Sources:

Mr. Alistair J. Crerar - United States
Mr. Jerrill F. Janik - United States
Mr. Dave Craft - United States
Mr. Paul Truhe - United States
Mr. Ed Geer - United States

References:

Unless otherwise specified, all models built, painted, photographed and are owned by the author.
Mortars in Miniature, Created and Maintained by Kevin Robert Keefe, Copyright © 2001 - 2008.
All Rights Reserved.


Alistair J. Crerar (r) Feb 1966 - Okinawa (For more on Alistair J. Crerar, and additional photos of the HOWTAR, please visit the Honor Roll Page 2)


	U.S. Model 98 HOWTAR Comments, suggestions, additional info?