Hybrid Cannon?

[intoodeep]

While surfing around I came across the photo below. Can you spot the obvious cross over?  Boy, I guess everything is trying to go Hybrid....   

P.S.- I know cannonmn will notice three issues with this one. 

[thelionspaw]

I noticed it right away. They used the wrong kind of rocks.

[Terry C.]

I got the main one.

Still looking for the other two.

[Cannoneer]

 This seems perfectly normal for San Francisco.

[seacoastartillery]

      Intoodeep,    Cannonmn has been on for over an hour now, and still hasn't jumped on this, so I guess it's O.K. for me to put forth a SWAG on the challenge you presented here.  One, I believe the people who mounted this bronze cannon used an iron mortar bed for an 8" or 10" Siege Mortar, Model 1861.  Two, The Cannon's below center trunnions are smaller than the mortar trunnion so they had to fabricate a collar to fit the bronze trunnion and the mortar bed, trunnion cradle/capsquare combo.  Three, it appears that there may be some Bronze Disease in the area of the Dolphins, the second reinforce and maybe even a bit on the first reinforce.  The only areas that appear to be unaffected are the 'easy-to-touch' areas which have certainly been pawed by little kid's hands loaded with french fry oil which is almost as good as the conservationist's fancy wax.

     Thanks for posting this oddity; is this one also in San Fransisco?  Is that the Golden Gate Bridge in the extreme background?  Is the gun located at the S.F. Maritime Nat'l. Hist. Pk.?

     Boom J, since it's on the left coast here, in San Fransisco, this SWAG may be way, way off in left field, but is your bronze cannon located at the Presidio, by any chance?

Regards.

Tracy

     

[A.Roads]

I think it is also quaint how they have combined (sort of) three main artillery services, a Field gun on a Land Service mortar bed mounted by the coast, giving a Sea Service impression! Adrian

[cannonmn]

I think everybody has it, I saw the two things anyway, the mortar bed and the trunnion bushings.  The trunnions stick out too far.  And the land piece near the water?  Good take on the hand-oil and preservation, but we'd have to check how much wear that induces, there are acids in hand oil too I'm told.  All the maintainers have to do with old bronze is keep it waxed, really.  Bowling alley wax is what one of my friends uses on all his collectible guns, on the wood, metal, all over, bayonets too, then he doesn't have to worry about anything getting on it from people's hands.

Yes this is certainly the piece that was on the lawn at the Presidio.  This particular gun as I recall is a French 24-pounder.  It was presented to the Mayor of San Francisco by the US Government when a couple of ship-loads of trophy cannons arrived after the Spanish-American war.  All the markings were recorded by the Government at that time and I have a copy of the transcription in my computer somewhere.

[intoodeep]

Hey everyone,

 Very interesting responces. I had posted this just for fun. As for the three crossover items. I was was just thinking simple.

1. Field piece on a Mortar Bed.
2. Different time period between the two pieces.
3. Different countries of origin.

 As for the location of this one. I believe this was in Puerto Rico but, I'll need to try to reconfirm that.

[Cannoneer]

   Tracy, your educated guess is absolutely correct and the redoubtable Cannonmn is even more absolute in his correctness. This gun is indeed located on the Presidio's lawn and it is a French 24 PDR. I would like to continue this quiz with a follow up question: What makes this gun unusual when considered with the rest of the Presidio's collection of antique bronze cannons? But, why bother, Cannonmn is just going to answer it, so I'll give the answer myself. The Presidio has one of the finest collections of bronze Spanish Empire cannons in our country, many cast in Lima, Peru in the 1600's.
Click on the guns' names.
www.nps.gov/prsf/historyculture/spanish-artillery.htm

[cannonmn]

What' nice about the group at Presidio and the one at Fort Point is that I can't see any definite evidence of bronze disease on any of them.  Usually when they are either dark brown/black, or smooth and shiny, bronze disease isn't active and the guns are relatively stable.  All those guns seem to fit one of the good  categories.  I wonder if the one at Fort Point (San Martin) was cleaned and preserved?  There's got to be a reason it is dark brown or O.D. colored and the othes are all green.  Perhaps it is more exposed to salt spray being much closer to the water, and that does something, not sure.  I'd like to get some input from the NPS folk on that, or maybe someone else would like to do it.

Tx for posting that site, I had not seen that one.

[Artilleryman]

The rear transom on the mortar bed has been modified or removed.  Interesting to see that they thought it was important to bolt the mortar to the monument base as if someone could move the gun and mortar bed.

[cannonmn]

as if someone could move the gun and mortar bed

Good observation.  I think the reason is building codes which have special requirements in that area due to earthquakes.  I wouldn't want to be near that thing when a 6.0 plus rattles things, the gun would definitely move in the horizontal plane if not bolted down.  Or a better way to put is that the stone platform will move and gun will want to stay where it is in space.

[Artilleryman]

Earthquakes didn't occur to me since we have to be told when we have one here in Michigan.

[Cannoneer]

What' nice about the group at Presidio and the one at Fort Point is that I can't see any definite evidence of bronze disease on any of them.

   After I read your post I went back and looked at all the pics again. It's funny how you notice things when your looking for something specific. Every cannon seems to have a glossy finish, or a coating of some kind that is reflecting the light off its surface. It's difficult to tell for certain from a photograph but your right, the barrels all appear to be in good shape. The Park Service in San Francisco is evidently doing a better job of preserving these bronze guns than our military branches in D.C., because they certainly appear to have had some form of protective coating applied to them.

[GGaskill]

I would bet that the nearly continuous onshore wind and other geographic features of the San Francisco area contribute to a less corrosive environment (the smog gets blown away, among other things.)