MBT-70
 

Hi,

Does anyone know if there is any reliable data on the level of armor protection (thickness/slope) planned for the production version of the MBT-70 available online? I haven't been able to find anything.

Thanks,

Adrian

Re: MBT-70
 

as only a few prototypes got built - It may not have gotten out of the mild steel prototype stage?.

Only articles I could find on it mention no thicknesses, but that it was to be layered armour (saw a mention of 2 layers so probably a simple spaced armour ?), but not of the Chobham type. That came later on the XM-1 that replaced it.

Andy

Re: MBT-70
 

I really don't know, but if you give me time, I could go down to aberdeen, and try to measure the MBT-70 itself, and look at my books.

This is from Hunnicutts' Abrams:

MBT-70 US Pilot
3 man crew
114,000 lbs weight combat

152mm Gun with 6 RPM Loader
48 rounds of 152mm
750 rounds of 20mm
6000 rounds of 7.62mm
40 MPH sustained speed on level road

ARMOR
Turret: Cast homogeneous armor steel inner shell overlaid with spaced high
hardness homogeneous rolled armor steel, welded assembly

Hull: Welded assembly of rolled homogeneous armor steel plate with some armor steel
castings and aluminum armor

Re: MBT-70
 

Thanks for the info!

No need to bother on the measurments, but thanks for offering. I'm not sure it would do much could in any case, as the only MBT-70's built we're mild steel prototypes.

Adrian

Re: MBT-70
 

I started a thread on Tanknet with my analysis of the MBT-70 protection; you can see it HERE

Very Early Calculations (may be disproved by Tanknetters)


This calculated gives us the following statistics:

Frontal Hull Protection: 253mm KE, 312mm HEAT
Side Hull Protection: 100mm KE/HEAT

Gun Mantlet Protection: 449mm KE/HEAT
Side Turret Protection: 194mm KE, 227mm HEAT
Rear Turret Protection: 63.36mm KE/HEAT

Re: MBT-70
 

Is it just me, or does that seem to be pretty low? From what I understand, the MBT-70 was supposed to be a very heavy and very big tank. I've looked before but no source gives you a straight answer. Why is that they still haven't released the armor figures? It has to be declassified by now.

Re: MBT-70
 

Hello, here is a nice website. It has pictures of the German prototype, as well as some interesting facts. The US prototype appears to incorporate the 152mm gun/launcher, which was the same as the M60A2 and the M551! That would have been quite a machine. http://forum.shrapnelgames.com/images/smilies/happy.gif

http://www.battletanks.com/mbt70.htm

Re: MBT-70
 

The US prototype appears to incorporate the 152mm gun/launcher, which was the same as the M60A2 and the M551

No, those were the short versions, the MBT-70 had a long barrelled 152mm gun.

Re: MBT-70
 

My friend, I did not mean to offend. Though the weapon was a longer barrel 152mm prototype, the fact that it was to incorporate the Shillelagh missile is still an amazing idea.

http://www.globalsecurity.org/milita...und/mbt-70.htm

"The US prototype was equipped with a 152mm gun launcher with an auto loader. It was capable of firing AP/HE/WP rounds and the Shillelagh Missile. The main armament was to be a long-barrelled improved XM-150 variant of the XM-81 gun/launcher mounted on the M551 Sheridan and the M60a2 Patton. This was a much more reliable weapon than the earlier variant, firing Sabot, HE, and Cannister rounds in addition to the Shilelagh A/T Missile, but the earlier weapon's reputation was such that it was a lost cause from the start. It had a coax 7.62 machinegun and a 20mm AA remote control gun in a separate part of the turret. It would pop up out of twin hatches and fire at the target. The German version had a 120mm autocannon, instead of the 152mm gun launcher."

There is an interesting review on Wikipedia: Here is the link

http://en.wikipedia.org/wiki/MBT-70

and

http://en.wikipedia.org/wiki/Shillelagh_missile

And for more pictures:

http://www.panzerbaer.de/types/bw_kpz_70-a.htm

http://forum.shrapnelgames.com/images/smilies/smile.gif

Re: MBT-70
 

Did anyone tell you, by the way, that the Shillelagh had a one mile minimum range?

Re: MBT-70
 

Actually it's closer to 1/2 mile. The MGM-51 had a minimum range of 730 meters. As I understand it, the ballistic track of the missile caused it to drop out of the sight/tracker's field of vision within the minimum-range envelope.

Adrian

Re: MBT-70
 

"Pop out of twin hatches and fire at the target"....?!
Sound like a trailer from Star Wars. No wonder the whole vehicle was a failure.

Re: MBT-70
 

Still, it was a very cool tank. The prototypes that never make it into service are actually more interesting than the stuff that does the real fighting. How many German Maus superheavy tanks saw combat service in WWII? Zero. How many books where written about the Maus? Dozens.

Re: MBT-70
 

Isn't the shelleleigh what they use in the Airborne light tanks that the 82nd has? I thought they hated them ...

Re: MBT-70
 

The MGM-51 Shillelagh actually had a full six inch diameter warhead twenty years before the TOW 2 was fielded, and packed a 15 pound warhead, almost twice the weight of the five inch warhead of the original TOW. It was closer in size and penetration to the first generation HOT missile. Those who fired it say the range is actually greater than the listed 3,000 meters, since it was infrared command guided and had no wire. One point I'd like to make about that factoid: there are restrictions on firing wire guided ATGMs over standing water. We've seen that fascinating CNN footage of a British Striker (?) firing a Swingfire missile at the abandoned Iraqi tank during OIF...the missile flies over a shallow pond, and several yards short of the far bank where the target tank was parked, the missile suddenly dips toward the water, strikes the surface, ricochets off the sandy shore, and manages to hit the target. If the target was further back from the shore, the missile surely would have missed its mark, having gone ballistic until the motor shut down. The Shillelagh and other non-wire-guided missiles aren't hampered by such water obstacles.

Basileus

Re: MBT-70
 

Why is there the restriction? How does the water below flight path affect the guidance system?

Re: MBT-70
 

I think the bigger issue was hating the system and the vehicle it was attached to. The M551 Sheridan was in many ways too light to handle the power of the missile, and so were its systems. Launching the missile had a tendancy to shake things in the turret loose and/or outright damage sensitive components. Furthermore, because of the vehicles weight the 152mm conventional (non-missile) ammunition that was carried meant that the vehicle had a very large engagement blind spot between which it could not hit a target with its main gun, but before the missile's minimum range. Of course the M60A2 was said to have suffered from the same blind spot.

Re: MBT-70
 

I may be speaking total BS here, but isn't that related to the fact that the wires aren't coated with some insulant due to weight constraints?
The signal-bearing wire is coiled inside the missile body (or around it in some earlier examples) and doubled or quadrupled for redundancy and equilibrium issues, so the specific weight of the wire is a critical issue to the missile performance. So electric insulation may have been disregarded and therefore lead to critical signal shunts over water.

Another possible case, which would be more consistant with the Striker anectode cited above, is that the wire just sinks into the water (sounds probable for even thin copper wire) fast enough to drag the missile back and down. That would be linked to the fact the the wire uncoils freely while the missile moves, but would also run against this fact, except at top ranges, because of the amount of reserve coiled wire available for unattended sinking before it affects the missile's flightpath.

Just my two cents, extracted from whichever data I could digest on the subject! So if anyone has better facts on this or wants to speculate further...

Re: MBT-70
 

It wasn't the missile, it was the conventional rounds that broke the fire control system. Every time the main gun fired a conventional 152mm round (that's a howitzer-sized round coming out of a 15-ton light tank), the recoil would cause at least two or three roadwheels worth of track to completely leave the ground. The shock would usually result in something breaking. The missile itself imparted negligible recoil.

AFAIK the M60A2 didn't suffer this damage, but the overly complex combination of gun and missile fire control was a maintenance nightmare, the missile couldn't be tracked at night or in inclement weather, and such conditions also rendered the primitive laser rangefinder nearly worthless. Later, when the Tank Thermal Sight was mounted on the 82nd Airborne's Sheridans, there were no problems firing at night or in moderate weather.

According to a former Sheridan crewman, the dead range issue was ironed out. Conventional rounds had an effective range around 1,000 meters, well above the minimum range of the Shillelagh (about 730 meters). In WinSPMBT, the gun has a maximum range of 20, and the missile has a minimum range of 20, which works out.

Basileus

Re: MBT-70
 

I concur with your former conclusion in that Striker footage, PlasmaKrab. The wires are too thin to have much insulation, hence standing water, chain link fences, power/phone lines etc. may short out the wires. The rather sudden dive the missile took toward the pond's surface didn't look like a voluntary course correction. As far as depth of the pond, I don't think the weight of the wire would impact missile guidance, as wire guided missiles are routinely fired from helicopters without adverse effects, even with rotor downwash.

Basileus