VIETAM ERA 4.2(107mm) MORTAR MOUNTED ON A U.S. HALF-TRACK

This reminds me of the three part model series by James Steel, titled Vietnam: Convoy Shotgun.

There was a feature in the no longer existing, MILITARY MODELER Vol 11 No 11 Nov. 1984.

This was Part 2 in the series and he buiolt this onto a Tamiya kit, 81 mm Mortar Carrier halftrack. Super cool ans detailed model but I never seen any reference photos of the prototype in 1/1

The vehicle in the article is pure conjecture and the historical facts presented are false.  It is a shame that it keeps getting reprinted.

  I flew convoy escort in gunships later during the war, and no one I saw ever used a half track. They also never carried mortars because we couldn't fly close to mortars being fired (high angle fire you know) and they wanted us as close as possible! IMHO, never happened. 

Good point Al. Either forward or backwards with very little traverse left or right.

Another point to discourage this would the the very limited traverse of the tube while mounted. As I understand the layout of the M4/M21 mortar carrier, the vehicle would have to be pointed at the traget. If your target is very fluid, you'd be constantly turning the truck to reallign the mortar with a target who'd be out of your zone before you had a chance to fire. Too, that would have exposed the lightly protected and critical radiator to direct fire, quickly turning your half-track into a road block.

I found a reference to the mentioned Kalbach book on Vietnam armor, the cover shot of the half-track has a very unconvincing mud application and not a single picture in the several Vietnam books I have shows anywhere near this level of muddiness, suggeting a lack of research on the builder's part:

Link to article sales page

I'd be willing to bet that this did not happen. On convoy escort, you need high rate of fire DIRECT fire, not slow INDIRECT fire, maybe have 60mm at the ready. The fight would be over before you got your second shot out. The basic M3 HT chassis would have needed to have the chassis strenghtened to accomodate the weight PLUS recoil forces of the 4.2" and why go through all that trouble when there were M106's and M125's in service. I have never seen any evidence that what you want to do ever existed.

There was a Brit 4.2" mounted on a modified HT during WWII but they did not remain in service for very long.

According to Squadron's M3 Half-Track in Action by Jim Mesko (1996), "While there has been some contention that US forces also used M3 variants when they first arrived in Vietnam during the mid-1960's, no hard evidence has yet surfaced to confirm this, which seems unlikely to have occurred" (Post-War page not numbered)

Further, Squadron's Armor in Vietnam also Jim Mesko (1982) and Gun Trucks by Timothy J. Kutta (1996)  and  Osprey's Vietnam Gun Trucks by Gordon L. Rottman  (2011) do not mention the use of half tracks as escorts, The first of these three shows a few pictures of RVN half tracks from the early 1950's, but nothing in US service in the 60's. The gun truck books both list the prime weapons as the M2 .50 caliber, M60 machine gun variants, the XM134 minigun and personal weapons such as the M14, M16 and M79 grenade launcher and say nothing of the use of mortars in escort duty.

As to convoy protective vehicles, they reference M35 deuce and a half and M54 (some carrying an M113 shell) and M51 5 ton trucks, as well as the M151 and M37 trucks, the M706 (V100) armored car, as well as some M48 Patton and M42 Duster tracked vehicles.