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Landships II -> Landships WW1 Forum -> Artillery -> Obusier de 149mm Mle. 1887 Krupp/FRC
Post Info TOPIC: Obusier de 149mm Mle. 1887 Krupp/FRC
CharlieC


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Obusier de 149mm Mle. 1887 Krupp/FRC
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The sad looking specimen (attached) is a 149mm Krupp/FRC howitzer captured by the AIF at Pozieres in 1916. It had been captured by the Germans in 1914 from the Belgians - the German designation was Belg 15cm K90. This gun has extensive shell damage - the barrage at Pozieres was something like 216,000 shells per hour so it's surprising that anything survived. The only visible marking on the breech is "Liege 1891".

Does anyone have any details on the weight and performance of this gun? It's intended to move the gun to a new location and the curator wanted some idea of the weight of the gun for the contractors. In the past the gun's axle has been cast into the concrete base which is going to make it problematic to remove.

Regards,

Charlie




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MCP


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Calibre :

149.1mm L/15

Weight of the barrel :

1000 kg

Weight of the breech block :

57 kg

Barrel lenght :

2.235 m

Barrel grooves

number :

32

depth :

12.137 mm

width :

2.5 mm

Rifling

length :

125 / 25 calibres

angle of twist :

7.2°

Battering charge :

2.8 kg of Grobkörniges Pulver

Powder Shell :

31.5 kg charge : 1.68 kg

Iron shrapnel :

31.5 kg charge : 0.45 kg of black powder

390 bullets x 24 g

Steel shrapnel :

31.5 kg charge : 0.425 kg of black powder

390 bullets x 24 g

Max. range :

?

Muzzle velocity :

300 m/s

Elevation :

+ 45° / - 0°



-- Edited by MCP on Saturday 9th of October 2010 01:51:06 PM

-- Edited by MCP on Saturday 9th of October 2010 01:51:43 PM

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CharlieC


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Thanks very much MCP - that's exactly what I was looking for. What's the source of the data?

Another query - what colour(s) were Belgian guns painted in 1914? Is it likely that the
captured guns were repainted Feldgrau or did they serve on in their original colours?

Regards,

Charlie


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WILLE. Carl Richard : Waffenlehre. Berlin : Verlag von R. Eisenschmidt 1896, p. 485, who reported data taken from "Belgique militaire" 9 September 1894.

Best,

Marco

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CharlieC


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This might be a bit technical for this forum but I'm curious....

On the breech of the Belgian howitzer there is a dished out part (attached) which matches the breech. How was obturation(*) handled in this gun?

Other Krupp breeches of this period had a pad which was screwed into the breech once
the breech block was pushed home but this gun doesn't have anything like this.

Regards,

Charlie

* obturation is the sealing off of the breech so propelling gases don't escape past the breech block. French guns of this period had a simple system - the de Bange obturator - which is still in use.



-- Edited by CharlieC on Monday 11th of October 2010 04:23:14 AM

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Rectalgia


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Probably "Broadwell Rings" going by Ian Hogg.  Full context from p60 A History of Artillery talking about the period around 1856 (and a bit after, obviously) and Krupp's introduction of cast steel gun tubes:
... Krupp's other innovation was his breech-loading system.  This used a wedge or block of steel sliding transversely in a slot cut in the rear end of the gun tube.  Movement was imparted to the block by a slow screw mechanism, and the sealing of the breach end against the escape of gas was done by soft metal "Broadwell Rings" let into the face of the breech-block where they mated with the face of the breech itself. ...

I think Ralph has a C73 in his collection and may be able to confirm the arrangement.  I haven't researched this much.


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CharlieC


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Sounds about right - I've asked for someone to look at the back of the breech to see if
there's a machined slot to hold the Broadwell ring. There is an article from Scientific American from 1882, linked from the Wikipedia page on Broadwell Rings, where the various obturators used in the 19th century are discussed.

The C73 had a different system - the breech block had a screw which pushed an obturation pad into the back of the breech when the breech was closed . When the breech was opened the first motion was to retract the pad back into the breech block.

Regards,

Charlie

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Rectalgia


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Thanks for the clarification and reference Charlie.

There's also some mention of "ordinary Broadwell rings" in the report of the US Chief of Ordnance to the War Department in 1879 (thence to Congress). Things are slightly more complex, we're looking at converted muzzle-loaders and the main purpose of the conversion is to allow pressure readings to be taken more easily through use of the breach blocks. In the case of the 3" rifle (Appendix H1) the CuP Rodman pressure-plug is more or less integral with the gas-check arrangement and despite drawings I'm still not getting a clear idea of the rings. And it may be that the Americans invented an extraordinary Broadwell rings construction - compound copper and steel whereas it may be the "ordinary" type were just copper.

Anyway, see House of Representatives Papers 1879-80 Vol 6 Ordnance No 1 part 2 vol 3 & ff, it should open at the correct Appendix. From a brief look through some of the other modifications it seems they might have been trialling up to 39,000 lb/in2 pressures and getting an amount of welding to the breech face with plain copper rings. Or I might be hopelessly confused.

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CharlieC


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It's fairly hard to pick up in the diagram on p.74 of the reference but it looks like there
is an outer steel ring of "L" section with a copper ring hammer welded or screwed onto the steel ring. I think the intent is to have the copper ring act as the gas seal between the rings and the breech wall. The steel ring would bear on the plate in the breech block to avoid the problems noted with welding copper rings to the steel backing plate.

Regards,

Charlie


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