MBT-70

[Basileus]

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

[Marek_Tucan]

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

[PlasmaKrab]

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

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...

[Basileus]

PlasmaKrab said:

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...

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