welty@lewis.crd.ge.com (richard welty) (07/21/89)
From: welty@lewis.crd.ge.com (richard welty)
In article <8033@cbnews.ATT.COM>, pierson@cimnet.dec.c writes:
*Historical interlude: ca 1890/1900 "seacoast mortars", typically around 12",
*were popular for coast defense.
12" sounds a bit high. 4.2" was very common. the only 12" seacoast
defense weapons i know of were guns, sometimes on a `disappearing' mount
(the gun was on a lever arm mounting and the recoil would drop the gun
behind a revement where it would be reloaded.)
[mod.note: A quick perusal of _Weapons of the Third Reich_ shows a 28cm
Ku:stenhaubitz (coastal howitzer) which is essentially a mortar, left from
pre-WWI, and a similarly-dated impressed French 27cm coastal mortar. Seems
large mortars were around at the time. (28cm = 11") - Bill ]
at Ft. Desoto park, just south of St. Petersburg, Florida, a 4.2"
battery of mortars has been preserved in fairly good condition.
the fort is actually a very representative sample of the kinds of
coast defense installation that the US was building on all of its
possessions at the time. there is a twin fort on the other side
of the shipping channel on Egmont Key; there is no surface access
to the key, and no effort has been expended on preserving this
installation.
the earliest 4.2" mortar installations grouped 4 such weapons
into each bay of a fort; the concussion of simultaneous firing
was such that the crews were incredibly abused; later installations
went to 2 guns per bay. the watervliet arsenal has a nice picture
of a 4 gun/bay site; they are trying to find one of the mortars for
their collection but have so far been unsuccessful.
* The objective was to shells drop onto the
*lightly (some times un) armored deck of battleships, etc.
it was only during wwi that ship designers realized that
with increasing angles of elevation on the main batteries
of ships, that the distances of engagement would increase,
which would therefore make plunging fire an issue. post wwi
designs were much less vulnerable to this type of coast defense
weapon.
and now for a question: until i toured the arsenal museum last
saturday, it had never occured to me to think about recoil and
mortars. the 4.2" coast defense weapons had no particular
provision for recoil, and the stress on the mounting and the
concrete foundation underneath must have been tremendous.
one of the museum staff informed me that an 81mm mortar
recoils with a force of 400g's; i guess that all of this is
handled by the large baseplate. are there any mortars with
special provisions for recoil, or is this considered an
unnecessary frill?
richard
[mod.note: From the same source, I note a number of recoil-compensated
mortars. These include a 5cm model designed for Stalingrad street-
fighting and a large 15cm (6") model. Neither was successful. - Bill ]
--
richard welty welty@lewis.crd.ge.com
518-387-6346, GE R&D, K1-5C39, Niskayuna, New York
Officer: Do you know how fast you were going?
Driver: No. The speedometer only goes up to 85dave@rnms1.paradyne.com (Dave Cameron (Consultant)) (08/02/89)
From: dave@rnms1.paradyne.com (Dave Cameron (Consultant)) In article <8481@cbnews.ATT.COM> welty@lewis.crd.ge.com (richard welty) writes: >12" sounds a bit high. 4.2" was very common. the only 12" seacoast [stuff deleted] >at Ft. Desoto park, just south of St. Petersburg, Florida, a 4.2" >battery of mortars has been preserved in fairly good condition. [stuff deleted] >the 4.2" coast defense weapons had no particular >provision for recoil, and the stress on the mounting and the >concrete foundation underneath must have been tremendous. [stuff deleted] >are there any mortars with >special provisions for recoil, or is this considered an >unnecessary frill? > Well i live here, picnic here, and the mortars [howitzers?] I saw were a lot bigger that 4.2" in diameter. 8" ?? however I do not have that on paper, and maybe they looked bigger than they were :-) They Did have gawd-awful big springs mounted under them. Could these have have been just to offset elevation loads ?? also there were concrete circles for 4 per bay but only two mortars (as you said) [looking at this impressive between-the-wars tech, never used, was a reflective experience] Dave Cameron
welty@lewis.crd.ge.com (richard welty) (08/04/89)
From: welty@lewis.crd.ge.com (richard welty) In article <8753@cbnews.ATT.COM>, Dave Cameron (Consultant writes: =In article <8481@cbnews.ATT.COM> welty@lewis.crd.ge.com (richard welty) writes: =>12" sounds a bit high. 4.2" was very common. the only 12" seacoast [stuff deleted] =>at Ft. Desoto park, just south of St. Petersburg, Florida, a 4.2" =>battery of mortars has been preserved in fairly good condition. [stuff deleted] =>the 4.2" coast defense weapons had no particular =>provision for recoil, and the stress on the mounting and the =>concrete foundation underneath must have been tremendous. [stuff deleted] =>are there any mortars with =>special provisions for recoil, or is this considered an =>unnecessary frill? =Well i live here, picnic here, and the mortars [howitzers?] I saw =were a lot bigger that 4.2" in diameter. 8" ?? apparently i got confused somewhere along the line. i have been convinced that these suckers really were 12". (i used to live there -- grew up in st. pete fl. haven't seen the installations at ft. desoto in a long time) richard -- richard welty 518-387-6346, GE R&D, K1-5C39, Niskayuna, New York ..!crdgw1!lewis.crd.ge.com!welty welty@lewis.crd.ge.com Officer: Do you know how fast you were going? Driver: No. The speedometer only goes up to 85