Excalibur

[GUNS]

News that the Excalibur shell is strictly a warm weather round(for now) is not good news for our M777's in A'gan.

Delivery of this new round is delayed until this fall or early next year. During testing it was discovered that cold weather drains the on-board battery faster than normal. The resulting drain shuts down the on-board guidance system.

The Excalibur can still be used but will not be near as accurate as planned and will not have the distance. At $80,000 a shell, I don't see many of these being used until the problem is fixed.

The Excalibur suppliers suggest if you keep the shells warm prior to use the shell should work fine. Heated blanket will have to join the gun equipment list.

 

[Gunnerlove]

What is "cold" weather? Because I don't work so well at -40 either.

 

[Michael OLeary]

Supporting link provided by GUNS:

http://www.strategypage.com/htmw/htart/articles/20060810.aspx

Excalibur Freeze Out
August 10, 2006: Excalibur has a case of frostbite. The U.S. Army, under the constant prodding of artillery officers in Iraq and Afghanistan, are hustling to get the Excalibur "smart shell" ready for deployment. The troops want the 155mm, hundred pound, GPS guided shell as soon as possible, even if all the kinks are not worked out. The first Excaliburs, that will reach U.S. and Canadian troops this Fall, will have a range of 23 kilometers, and reliability of only about 75 percent.

(More at link)

 

[geo]

reliability of 75%......
Yetch!

 

[Kirkhill]

What's the CEP on the unreliable 25%?

 

[Meridian]

80,000$/shell = 75% reliability.

Complete novice, but, curious:
-How much does a typical/standard shell cost, and what is its related reliability?
-How many of these do we put down-range on a typical fire mission?

 

[Kirkhill]

In the not-so-long-term I am still betting that physics will win out on the PGM discussion.

The high-g's of a cannon launch are going to be a continuing problem for electronics (and mechanical flight surfaces) to overcome.  Missiles with their "soft-launch" low-g launches are much more likely to put rounds into the air without damaging the payload.

For PGM delivery I think that Arty is going to end up being much better served with vehicles like the N-LOS Netfires or the GMRLS systems.  Their ranges of 40 to 70 Km for the N-LOS PAM and LAM missiles or 70 to 100 km for the GMRLS,  NLOS carrying a Hellfire sized 12 kg warhead and GMRLS carrying an 82 kg warhead vs the 47 kg "warhead" of the Excalibur give more coverage than the 155mm can deliver.  And prices are broadly comparable (60-100 K for the NLOS and 100 K for the GMRLS).  For that matter even the Air Forces JDAMs (25 k), JDAM-DAMASK (35 k) or Small Diameter Bomb <114 k) are often cheaper.

For area saturation - guns and bullets.  But for precision, either ground-launched arty missiles or air force launched bombs or missiles.

 

[Old Sweat]

The so-called 25% unrelabiity factor is interesting as it implies either a failure of the guidance system to function or the sending of false directions to the control surfaces. If the guidance system fails, then the round is essentially a normal round and should, repeat should, have the accuracy of a normal projectile. If, however, incorrect data are produced by the guidance system, then the mind boggles at the results. Having said that, the ability to alter the trajectory is limited, and the round is hardly likely to (using a ridiculous example) turn through 3200 mils and take out brigade headquarters.

There were cold weather restrictions on ammunition in the past. Proximity fuzes like the M513 and M514 were restricted in cold weather; however this was because of the effect of cold on the acid that was freed by the shattering of a glass vial on firing and reacted with lead plates, thus becoming a wet cell battery. The Honest John rocket also was designed to be fired within a fairly narrow temperature range and the transportation vehicle had an auxilliary heating system to condition the rocket motor. Some of the more, ahem, mature members may also recall that there was a minimum temperature limit for firing the 3.5-in rocket launcher, although if I recall correctly this was based on concerns for crew safety as there was a danger of exhaust gases blowing back as the motor contiuned to burn after it left the tube.

 

[Kirkhill]

The so-called 25% unrelabiity factor is interesting as it implies either a failure of the guidance system to function or the sending of false directions to the control surfaces. If the guidance system fails, then the round is essentially a normal round and should, repeat should, have the accuracy of a normal projectile. ...

I guess my concern would be with those control surfaces and what attitude they might be in when the guidance or control mechanism fails.  Presumably they could act as brakes and cause a "short", as wings and cause an "over" or guide the round to any variety of other "targets".  Not including (as you point out) Bde HQ or the original firing point.

 

[geo]

Some of the more, ahem, mature members may also recall that there was a minimum temperature limit for firing the 3.5-in rocket launcher, although if I recall correctly this was based on concerns for crew safety as there was a danger of exhaust gases blowing back as the motor contiuned to burn after it left the tube.

Remember quite well wearing a belaclava in summer AND winter to protect my face from the residual solid propellant of the 3.5..... lots of fun.

 

[Loachman]

there was a minimum temperature limit for firing the 3.5-in rocket launcher, although if I recall correctly this was based on concerns for crew safety as there was a danger of exhaust gases blowing back as the motor contiuned to burn after it left the tube.

Chunks of unburnt propellant, actually, which could penetrate right through a lip.

 

[Old Sweat]

You may very well be correct, and I thank you for sorting out the issue. The point where we both agree is that the propellant did not burn completely before the rocket left the tube, which was not a good thing.

 

[TangoTwoBravo]

I liked the plain old dumb rounds fired by smart crews controlled by smart FOOs/FOO techs.  The enemy sure didn't seem to like them.

 

[Bruce Monkhouse]

I liked the plain old dumb rounds fired by smart crews controlled by smart FOOs/FOO techs.  The enemy sure didn't seem to like them.

.
...and at a MUCH better price/reliability also.

 

[Old Sweat]

I must admit that I have been wonering about the utility of the Excalibur after reading about the employment of conventional artillery in theatre. The relatively few number of rounds slated to be procured indicate that it would be reserved for very high priority missions.

 

[geo]

they've been using dumb rounds so far.....

 

[Cloud Cover]

The relatively few number of rounds slated to be procured indicate that it would be reserved for very high priority missions.

Such as a Lincoln Navigator [Lebanon] or high end luxury land rover [Afghanistan] with the passenger seat lowered to the floor?

Notice the fine sand and dust in the picture posted by GUNS. The M-777 must be hellacious to keep in clean working order over there. The gun crews must be doing one hell of a good job to keep them ready for fire support. 

 

[Old Sweat]

Exaclibur would not be of much use against a moving target. Now, if the vehicle was parked outside a farmhouse, I would be inclined to fire one at the house, followed by several rounds of fire from every gun in range for effect using air burst twenty or thirty seonds later to get the attention of anybody scurrying around outside. That is what is known, in gunner speak, as a murder mission.

 

[Cloud Cover]

Exaclibur would not be of much use against a moving target. Now, if the vehicle was parked outside a farmhouse, I would be inclined to fire one at the house, followed by several rounds of fire from every gun in range for effect using air burst twenty or thirty seonds later to get the attention of anybody scurrying around outside. That is what is known, in gunner speak, as a murder mission.

For sure not a moving target, although that would be nice capability to have from an arty piece, eh!!!! 

 

[Bruce Monkhouse]

For sure not a moving target, although that would be nice capability to have from an arty piece, eh!!!! 

Oh, we do it...just not at $ 80, 000 adjustments.....