Parrott guns safe or not?

[major bill]

Parrott guns seem to have had a poor reputation for safety. It does appear that some burst or had shell explode in them. Is the view of them warranted? We must have some artillery folk who can clue us in.

 

[unicornforge]

I'm sure that you already know that cannons and even tank barrels were and are rated for how many rounds they were/are expected to fire before the barrel fails. I humbly suggest reading the free online book, "The Artillerist's Manual" .
http://www.artilleryreserve.org/Artillerists Mannual.pdf

 

[Saphroneth]

Parrott guns seem to have had a poor reputation for safety. It does appear that some burst or had shell explode in them. Is the view of them warranted?

It's important to think about what they're to be compared to. For example, the British Armstrong gun also had a poor reputation for reliability, but nobody ever seems to have been killed or even seriously hurt by an Armstrong vent piece blowout while the Parrott guns sometimes inflicted a fearful toll in dead on their own side.

 

[rebelatsea]

It's important to think about what they're to be compared to. For example, the British Armstrong gun also had a poor reputation for reliability, but nobody ever seems to have been killed or even seriously hurt by an Armstrong vent piece blowout while the Parrott guns sometimes inflicted a fearful toll in dead on their own side.

Probably because the BLR danger zone was directly above the breech, whereas with a bursting parrott it could be and was all around the gun.

 

[Saphroneth]

Probably because the BLR danger zone was directly above the breech, whereas with a bursting parrott it could be and was all around the gun.

Most likely. The vent piece was to some extent designed for that purpose, as I understand it - it was, literally, a vent piece and as such it would blow before anything else (thus why each gun came with two spares).

To answer the question, basically the thing which made the Parrott problematic was the metallugy of the gun. The Parrotts were largely adopted in a hurry as war came and weren't really properly tested (ditto with the larger naval Dahlgrens, which also had a problem with bursting) and so while they were less fragile than previous cast-iron guns they were still failure prone.
Basically a cast iron gun is cheap and will randomly explode, a wrought iron gun is good and expensive, and a Parrott gun is somewhere between the two.


(On the testing point - I've not managed to find any data corresponding to accuracy tests of the Parrott field guns...)

 

[UCVRelics]

The casting on the Parrotts was suspect but another thing you need to look at is the rounds fired etc. In my US Army days all artillery pieces were bore scoped and had pullover gauge readings taken before firing. All rounds had a EFC (Effective Force Charge) rating which was annotated in the weapons data card that was with each gun. At certain points the barrels were changed. This things did not exist during the CW.

 

[redbob]

The Parrott's used a cast iron tube whereas the Ordinance Rifle used a wrought iron tube which was stronger. When the Parrott's distinctive reinforcing band was welded on to the tube, this also tended to weaken the cast iron in the breech area. Keep in mind that once a tube failed, this may have planted the idea in the mind of artillerymen that the Parrott was unsafe; that said, I have never seen a report of an Ordinance Rifle's tube failing. Also, as soon as the war ended, so did the Parrott's career while the Ordinance Rifle soldiered on for another 20 years. And while the Ordinance Rifle's tubes were more expensive ($330 vs, 180 for the Parrott) they may have proved to be the better bargain in the long run.

 

[major bill]

Redbob, are you sure the Parrott reinforcing band was welded on? I have hear a different story on how it was attached.

 

[redbob]

Redbob, are you sure the Parrott reinforcing band was welded on? I have hear a different story on how it was attached.

Welded to the extent that it was heated and forced over the breech. I have read accounts where the band would slip and block the vent rendering the gun useless.

 

[rebelatsea]

Welded to the extent that it was heated and forced over the breech. I have read accounts where the band would slip and block the vent rendering the gun useless.

Indeed that was the standard method of attaching reinforcing bands in both Parrott and Brooke MLR. In the case of the Brooke guns Tredegar seemed to have got it down to a fine art, whereas Selma didn't always and there are surviving examples where the reinforcing bands have separated. Having said that Armstrong / Woolwich guns sometimes had the tube loosen inside the reinforcing ,but this was always, as far as I know discovered on proofing.