Heavy Tactical Aircraft Rockets

Sauragnmon · June 22, 2009, 09:18:36 AM

I was looking at the Tiny Tim just now, and I had myself to thinking - what an odd bloody caliber that rocket is. I know it's basically a rocket motor jammed on the arse end of a 500 pounder, so that's explainable, but it had me to thinking, what about taking a Naval Gun round and putting a rocket booster on it? It'd probably have a better flight profile, being that they're designed to cover a distance rather aerodynamically so they hit the target with some semblance of accuracy. So you take this heavy naval shell, like a 16" round, and you build it with this rocket motor on the arse end, and you hang it centerline under something that's got enough stones to lift it.

I mean it wouldn't be the first time a naval artillery round was adapted for use by an aircraft - remember, Arizona was essentially sunk by IJN 16" naval rounds modified for aircraft drop as AP bombs.

Or have I just slipped off me rocker? You folks can decide.

Cliffy B · June 22, 2009, 09:25:48 AM

I think we need to start building! Could a PBJ carry one of these suckers? Get a group of them together for a shipping raid and just sit back and watch the fireworks!

Hobbes · June 22, 2009, 09:41:41 AM

Naval rounds use very thick casings to survive being fired out of a gun. Bomb casings can be thinner, so you get more explosives in the same total weight. Bombs have to be as aerodynamic as gun rounds, so that's no argument.

Sauragnmon · June 22, 2009, 09:45:59 AM

I could imagine a PBJ might be able to carry one of them. The casing might well be able to be smaller in some parts, but I was equally thinking that keeping the ballistic cap would be good, for punching through a hardened target.

Cliffy B · June 22, 2009, 09:53:50 AM

Keep the casing (and reinforce it?) to make them armor piercing! Primitive unguided Harpoon

kitnut617 · June 22, 2009, 09:56:18 AM

My comment in the Tiny Tim thread about the British 'Uncle Tom' RP is just that Sauragnmon, it was an artillary armour-piercing shell attached to a group of six 3" RP motors and had a 11 1/2" shell head diameter. My mistake in the other thread was that the photo I've seen of one hanging off a Seafang was actually a 7.2" shell attached to a group of three 3" RP motors.

The Uncle Tom was developed to attack large warships like a battleship without getting in too close to the defending Triple A. I'm just re-reading BSP-Hypersonics, Ramjets & Missiles again and found another photo of the Uncle Tom installation under a Mosquito which could carry two of them plus there's a short paragraph which covers these missiles (page 88). A development of the Uncle Tom was a RP code named Red Angel. There's a couple of photos of these hanging off a Wyvern on page 89.

NARSES2 · June 24, 2009, 03:58:39 AM

The reason for the obscure calibers was quite often down to what was available at the time. More often then not the casing used was standard oil drilling line pipe and this uses API (American Petroleum Institute) dimensions and specifications. A lot of the reasons for the the dimensions used is purely down to what the US mills were capable of producing when the need for this type of pipe came about - same for a lot of other traditional specs.

Naval gun barrel calibers were also limited to what could be produced at the time rather then what the architect wanted and these got larger as the steel making technology got better.

The British 3" RP was simply down to the fact that this was the maximun size that the propellant material could be drawn into (not sure if this changed latter)

Quite often in so far as munitions are concerned the designers took what ever was available off the shelf for the casing. There's some lovely examples of this when you read the pre WWI histories of companies like Vickers and Beardsmores etc. Used to have a lot of these in the library at work, fascinating stuff.

kitnut617 · June 24, 2009, 07:18:18 AM

From what I've read it's somewhat along the lines NARSES2 has said, except the 3" pipe was just generally available pipe. It was piping any plumber could buy at the time and even now. Being in the steel industry (I had my Lloyds Pressure Welding Tickets in the UK and 'B' Pressure Ticket over here in Alberta in my earlier days) I can tell you that 3" pipe isn't 3" OD (Outside Diameter). All plumbing piping from 1/8" to 12" comes as what is known as 'Nominal' and is sized as a 'schedule'. Nominal is an variable inside diameter where the OD stays the same but the ID (Inside Diameter) changes depending on the schedule (SCH) . STD pipe (most commonly used) is generally the equivalent to SCH40 up to 8" pipe (the wall thickness being the same).

3" pipe for instance is actually 3 1/2" OD, where 3" SCH5 has a wall thickness of .083" which makes the ID 3 5/16", and 3" SCH40 has a wall thickness of .216" which makes the ID 3 1/16". IIRC the 3" pipe used in the RP's was 3" SCH80, which has a wall thickness of .300" making the ID 2 15/16" (there abouts)

But we can be certain it wasn't 2 1/2" pipe that was used because the OD for that is only 2 7/8". Pipe sizes bigger than 12" are generally what is quoted, 14" pipe is 14"OD and so on up to the biggest pipes (for example, 60", or even more)

Just to confuse things though, today you can get steel pipe with 3" OD, over here it's called HSS (Hollow Steel Section), in the UK it's called RHS (Rolled Hollow Section[or Steel, I can't quite remember]), these pipes are a more modern size and I'm not sure that they were available back during the war and are used in structural designs (buildings, drilling rigs, bridges etc.)

Ed S · June 24, 2009, 08:48:40 AM

Quote from: NARSES2 on June 24, 2009, 03:58:39 AM
The reason for the obscure calibers was quite often down to what was available at the time. More often then not the casing used was standard oil drilling line pipe and this uses API (American Petroleum Institute) dimensions and specifications. A lot of the reasons for the the dimensions used is purely down to what the US mills were capable of producing when the need for this type of pipe came about - same for a lot of other traditional specs.

Naval gun barrel calibers were also limited to what could be produced at the time rather then what the architect wanted and these got larger as the steel making technology got better.

The British 3" RP was simply down to the fact that this was the maximun size that the propellant material could be drawn into (not sure if this changed latter)

Quite often in so far as munitions are concerned the designers took what ever was available off the shelf for the casing. There's some lovely examples of this when you read the pre WWI histories of companies like Vickers and Beardsmores etc. Used to have a lot of these in the library at work, fascinating stuff.

Some things never change. The GBU-28 Bunker Buster developed and used during Desert Storm consisted of an common 8" Howitzer barrel filled with explosives and then a hardened nosecone and guidance package added.

http://www.fas.org/man/dod-101/sys/smart/gbu-28.htm

Ed

kitnut617 · June 24, 2009, 10:11:13 AM

Quote from: Ed S on June 24, 2009, 08:48:40 AM
Some things never change. The GBU-28 Bunker Buster developed and used during Desert Storm consisted of an common 8" Howitzer barrel filled with explosives and then a hardened nosecone and guidance package added.

Ed

I quess that's one way of disposing of worn-out gun barrels

NARSES2 · June 25, 2009, 02:47:08 AM

Quote from: kitnut617 on June 24, 2009, 07:18:18 AM

Just to confuse things though, today you can get steel pipe with 3" OD, over here it's called HSS (Hollow Steel Section), in the UK it's called RHS (Rolled Hollow Section[or Steel, I can't quite remember]), these pipes are a more modern size and I'm not sure that they were available back during the war and are used in structural designs (buildings, drilling rigs, bridges etc.)

RHS, CHS in the UK and Europe (rectangular Hollow Section and Circular) can't remember what the non circular/not rectangular is called (retired 2 years now) and it wouldn't have been available back then. Probably a 70's inovation. Sizes are interesting - although they are listed in metric all the metric sizes equate to "traditional" imperial sizes

As for the British 3" RP it was the maximum extrusion size of the propellant core, and probably didn't require to accurate a size for the casing, and as you say 3" tube was/is one of the most available sizes of the shelf. Probably welded as well, rather then seamless ?

kitnut617 · June 25, 2009, 08:24:44 AM

Quote from: NARSES2 on June 25, 2009, 02:47:08 AM
RHS, CHS in the UK and Europe (rectangular Hollow Section and Circular) can't remember what the non circular/not rectangular is called (retired 2 years now) and it wouldn't have been available back then. Probably a 70's inovation. Sizes are interesting - although they are listed in metric all the metric sizes equate to "traditional" imperial sizes
As for the British 3" RP it was the maximum extrusion size of the propellant core, and probably didn't require to accurate a size for the casing, and as you say 3" tube was/is one of the most available sizes of the shelf. Probably welded as well, rather then seamless ?

Ah! yes now I remember --cheers.

I think it would have been welded pipe as it was cheaper to produce.

Off-Topic but here's a little story, while still in the UK I had a job I was making where the designer insisted that we use 40mm square RHS, wasn't allowed to use 38mm (1 1/2") so after a lot of searching some was found in Switzerland -- only it would take four months before we could get it. The designer didn't seem to worry so the material was ordered and it arrived about four months later. When I went to use it though I burst out laughing, it had 'Made In the United Kingdom' printed on it every foot or so but we couldn't get it in the UK

NARSES2 · June 26, 2009, 02:35:18 AM

Quote from: kitnut617 on June 25, 2009, 08:24:44 AM
Ah! yes now I remember --cheers.

I think it would have been welded pipe as it was cheaper to produce.

Off-Topic but here's a little story, while still in the UK I had a job I was making where the designer insisted that we use 40mm square RHS, wasn't allowed to use 38mm (1 1/2") so after a lot of searching some was found in Switzerland -- only it would take four months before we could get it. The designer didn't seem to worry so the material was ordered and it arrived about four months later. When I went to use it though I burst out laughing, it had 'Made In the United Kingdom' printed on it every foot or so but we couldn't get it in the UK

I bet it was rolled to order as well

I can tell you lots of stories like that. Stuff manufactured for Continental European or US standards and not offically for sale in the UK. Most of thats come to an end with the adoption of "Euro-Norms" as part of the BSI Standards. Still fun though when a lot of old blueprints were drawn in imperial, using things like AS and BSF etc

Jeffry Fontaine · July 18, 2009, 11:36:38 AM

An easy conversion for a large aircraft rocket would be to consider scale-O-rama of an aircraft rocket from a larger scale model to a smaller scale subject. This would work if you are able to source a 1/24th or 1/32nd scale rocket for a 1/72nd scale or 1/48th scale project. I did this as an interim solution prior to the resin 1/48th scale Tiny Tim aircraft rockets becoming available in resin from KMC and later Squadron's 'True Details' product line. The fins were a bit thick but that could be addressed by sanding or replacement with smaller thickness card stock.

Another option is to find the Revell 1/48th scale Peterbilt truck and trailer kit that has a crated Honest John rocket included in the kit. The rocket is crated up for transport but will assemble into a complete rocket. The plus side to this option is that you get a 1/48th scale truck and trailer rig with your rocket purchase. This large rocket could be used as is or the fins could be cut down and the warhead could be replaced with something a bit smaller in diameter if you want to disguise the origin of your WHIF weapon.