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 The Argus |
Sterling as MPA |
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Posts: 396 (09/16/07 23:39:08) Umpire |
I mentioned this ideqa over on another board I frequent, and bloke over there wants to do a rough simulation. I've got the pilots notes of the Sterling I, II and IV, so we've got the fuel figures, but I can't find my Janes (packed up for the big move) , and we really need bomb bay dimentions, and recomended ASW ordnance load (yes I'm looking at you Mark).
shane Rule .303
Shoot straight, you bastards. |
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 MarkLBailey |
Re: Sterling as MPA | ||
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Posts: 1106 (09/17/07 02:36:53) P-76 Pilot |
StIrlings.
Hmmm. Heh. OK, ASW load. Minimum at maximum range 2000lb. This is the Sunderland gross load and that was normally eight 250lb Mk XI DC. This was a modified Mk VIII with a concave nose to reduce ricochet, and this was the standard air-dropped DC from 1942. OK, the normal Stirling bomb bay was built for seven 2,000lb bombs in the main bay OR eighteen 500lb bombs in the fuselage and six in the wing bomb cells. Now the 500lb GP bomb was 12.9" x 71". The Mk VII DC (ship dropped) was 17.65" x 27.8", add a pointy end and a draggy end... and it is probably still too fat! Redesigning the wings is probably not do-able so we are stuck with 250lb DC in those cells with their 170lb amatol charges. That's OK, we can put Mk VII (290lb amatol) in the bomb bay and then we have big bangs in the centre of the pattern and the 250's still extend the coverage of the pattern nicely anyway. OK, I want the wing cells. Six 250lb Mk XI DC. That gives me three attacks. This is nice because of the Stirling wing cells, into which the 250lb DC fits. This would give two really nice patterns of four DC each with something all other acft lacked, both centreline laid DC and a side offset. The wing bomb cells would otherwise be nice fuel tanks, but they are very small and to be blunt you'd be better off with a huge tank in the bomb bay, reducing its size overall. But as it was built for 2000lb bombs (actually a 1900lb bomb) which was 19" wide, it will take 500lb Mk VII! This is very, very good. I already have three attacks maximum, which is a lot, so I want six Mk VII. And just because I like MPA guys (my father's cousin was one with 10 SQN), another 3 gives them options to really make a U-boat's life really exciting. Not to mention brief. So I want the wing cells (6 x 250lb Mk XI) and nine 500lb Mk VII. Now it gets more interesting. I only need half the weight capacity of the wing cells but all of their volume. But I have still liberated 1,500lbs of weight from the wings. I also do not need half of the bomb bay weight. So that liberates 4,500lb of weight from there. There will be a bit more because there is structure (shackles etc) I now do not need. That's 6,000lb freed up... to devote to more fuel. I'd also like at least a lick and a promise to U-boat flak suppression. I'd REALLY like two .50cal in the nose turret. The .50 cal can reach out and touch someone. I'd really, REALLY like a pair of 20mm there to reach out and touch someone at longer range. We can lose the dorsal turret. Due to CG reasons we can't lose the tail turret and a tail turret is a seriously useful place to have a pair of eyes and 4 x .303 will suppress the hell out of a U-boat's flak for the second and third attacks. I now need that tail turret, it buys me tactical options. I want two observation blisters aft port and stbd for more eyes and I also want two bunks, a tea urn and a hotplate with a small table seating 2. This beast is going to be doing long sorties and that buys me a new world of fatigue management. I want to be able to get people rested in rotation. There is basically no fighter threat, these boys won't be messing about close in over Biscay because we have Sunderlands and Blackburn Nutcrackers for that, they will be deep Atlantic specialists Cheers: Mark |
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Roller007 |
Re: Sterling as MPA | ||
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Posts: 1070 (09/17/07 03:01:13) Uncle Sam
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Ummm Bomber Command would turn them over to Coastal Command why? Also Coastal Command has options on B-24's which Bomber Command doesn ot so why take the Sterling?
Just wondering. Russ / Roller007 |
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MarkLBailey |
Re: Stirling as MPA | ||
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Posts: 1106 (09/17/07 04:02:49) P-76 Pilot |
Stirling, not 'sterling'! It was named after the castle not the currency.
The Stirling was flak bait. it could not go above 16,500' with a bomb load and ran out of puff at 20,500'. In FFO the RAF is going high altitude with a vengeance because we have cut the size of Bomber Command by at least 30-40% through dispersing it to the Med and Far East. Much wailing and gnashing of teeth from Bomber Harris. The kicker is that he has a certain inventor's high-altitude geodetic super-bomber, the Vickers Victory, entering service now to take the burden off the current and definitely dodgy RAF high altitude bomber (Wellington Mk V), and an even bigger, better, badder high flyer, the six-Centaurus powered canard Vickers C under feverish development. OK, it will probably be too late for Germany but when that beastie flies into the first USAAF Pacific B-29 base and all of a sudden makes the B-29 a medium bomber it should impress the heck out of the Japanese. What all this late-night gibbering means is that the Stirling is out of date as a bomber. It cannot carry the high capacity bombs like Cookie and has three times (IIRC) the loss rate of the Lancaster for each ton of bombs dropped. It is just too much investment for too little return now. SO production will be ramped down and it will become Coastal Command's new MPA, for which it is actually very well suited because Shorts designed it. It's altitude restrictions do not matter, and its exceptional manoeuvrability at low altitude is a real boon. The production capacity released will go into the Lanc/Manchester production, I guess. Manchester with the fixed Vulture engine (Shane christened it 'Bustard'. Ahem.) is the el-cheapo Far-east heavy bomber. it is good enough. Cheers: Mark PS, this port is pretty good! |
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The Argus |
Re: Stirling as MPA | ||
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Posts: 396 (09/17/07 05:08:45) Umpire |
Well Mark I ALWAYS have trouble spelling the stierling word as well you know, so stop picking on me!
Ok I just happen to have discovered my pilots notes for the Stirling, and no you can't have the wing cells on the VLR vairent. There's 438 galls of juice there, thats an hour's flight at MAX RICH continous, almost 2 hours at 5,000' on weak mixture @ 2,400rpm +2lb boost on 100 octane (flat chat cruise for the Herc VI). You no getty that - greedy man. To cut a long story short we have 2,254 galls in the wings, + 438 in the wing bomb cells for 2,692 galls all up with no FFO mods. Flight profile Climb to 5,000' and cruise @ 160 mph all the way out and back, on Herc VI. Climb @ 70,000lb - 20 miles, 50 galls 2,672 left Cruise @ 65,000lb, 5k' 160mph, 2,300rpm = 228 gph 2672 - 10% reserve = ~2,400 galls 2,400/228 = 10.5 hours 10.5 x 160 = 1680 air miles -> op radius is 840 air miles. This is conservative, aircraft in BC trim, all numbers rounded down, it takes no account of redcing weight and it's all still air conditions. This is presuming I'm reading the tables correctly. How much more do you want Mark? On the bow guns, I think you're going to have to be content with a pair of .303 brownings untill 43-44, the mid upper I though we might retain for Biscay bombers, but strip off for the Gap fillers. shane Rule .303
Shoot straight, you bastards. |
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MarkLBailey |
Re: Stirling as MPA | ||
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Posts: 1106 (09/18/07 00:26:54) P-76 Pilot |
Nope. I want the wing cells becuase that is what the OR blokes will want.
Looking roughly at the numbers, I think that adding the wing cells with their 170lb of burster increases the U-boat kill percentage from a single stick of 4 Mk VII DC by roughly 60-80% by adding 4 Mk XI. This is a very serious point and Coastal Command (they invented operational research evaluation) will make this point long and loud. Those wing cells make the Stirling the deadliest MPA in the sky, no joke. 1 gal is about 6.5lb of fuel. So I'll swap the 438 gallons of juice there for about 923 gallons of juice in the bomb bay. That's roughly 3180 gallons for a 13.7 hour sortie. This acft, now about 60-80% more effective in attack than a Wellington, is already looking exceptional. Now we feather one engine on the transit legs and cruise merrily on about 80% of that fuel consumption... It adds up fast. Agree that the Mk I MPA will be a BC standard with a paint scheme and different radios. But that is just the start of the mod path. Trust me on this one, the pattern you get with those wing cells makes a significant difference. If you really, really want them for range, the two inners could go, but I do not see the need. Cheers: Mark |
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Roller007 |
Re: Sterling as MPA | ||
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Posts: 1070 (09/18/07 04:02:40) Uncle Sam
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So what are you going to tow those Hamilcar gliders with then? He's right on the pattern the cells would give Shane. It would be a big selling point. Mind you losing a ton more ammo means you can put in the 800 lbs ASV. You'll also need some spots as well which may require some APU's.
Russ / Roller007 |
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The Argus |
Re: Sterling as MPA | ||
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Posts: 396 (09/18/07 07:24:29) Umpire |
How about we keep the wing cells as is, and leave tankage or DC's as an open option for flexiability's sake? It's not like there's any extra work involved either way.
Remember OR is but a new born babe at this point. The Certainty and Influence of their conculsions in 42-3 isn't up to 44-45 standards. Hell it's a nice little data point for them study. shane Rule .303
Shoot straight, you bastards. |
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MarkLBailey |
Re: Sterling as MPA | ||
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Posts: 1106 (09/19/07 02:19:55) P-76 Pilot |
Agree. Leave them as is and you buy all sorts of mission flexibility and tactical options at no cost.
This means you could do a max fuel load option for extreme range, and carrying even 4 Mk VII out an additional day's steaming (250nm), to get a plane over a convoy saves ships. Yes, ORE was new at this stage, but it was getting on its feet and aircrew were working on more efficient patterns themselves. The Wellington experiences in western approaches were where that came from. The critical lesson of 1917-18 had been learned by the CC men by this stage, that while sinking U-boats was nice and earned medals, saving ships from being sunk was what it was all about. Stirling already had slot-in tanks for the wing cells. It would be a minor job to develop slot in tanks for the bomb bay rather than one big, permanent fitting. Yes, more pumps etc are needed, but in the first series of mods to start turning Stirling into the longest-ranged MPA, possible, I think that the removal of the dorsal turret will occur, and they will buy the needed weight. Stirling will be a very good MPA, it is strong and has excellent performance at low altitudes, and can be modified for more range. Above all, in the free-fall A/S weapon era, it has a built-in 'edge' in combat effectiveness. The wing cells really do make a difference. I suspect it would serve post-FFO well into the 60s. Cheers: Mark |
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The Argus |
Re: Sterling as MPA | ||
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Posts: 396 (09/30/07 00:34:50) Umpire |
Mark,
Have you got any indication of the altitudes they'd like to be flying? shane Rule .303
Shoot straight, you bastards. |
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MarkLBailey |
Re: Sterling as MPA | ||
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Posts: 1106 (10/03/07 05:18:31) P-76 Pilot |
Just back in town. This is edited so it makes sense.
Transit would be at a cruising altitude where maximum time on station over the convoy would be wanted. An alternative to this would be a low level radar search patrol using ASV out to a closer convoy, doing a partial search of its track. Altitude for radar and visual search would be 4000-5000' depending on weather. Visual/radar search altitudes would be 2000-5000' depending on weather. In bad weather, the MPA might be bucking along at 300' just under the cloud base, for example. In clear, calm conditions, you really can see a periscope feather from 5000' when it is 5 miles away. For distant convoys, a 3-engine transit at economical speed and altitude would be the norm, with ASV turned off to save it for sweeping the water around the convoy. Probably (unless the convoy was under attack), the MPA would sweep the convoy itself to look for trailers and then work ahead, beating the sea with both radar and visual search 5-50 miles ahead. They would make sure to come back over the convoy every couple of hours to check again for trailers and for morale. Nothing helped morale more than seeing the MPA when convoys were in tiger country. The impact was striking, fewer stragglers and rompers, for example. Cheers: Mark |
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PMN1 |
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Posts: 12 (12/12/08 13:39:25) |
If wing cells would give a Stirling MPA an advantage over other potential MPA, what effect would there be on those MPA if they were to use external carriers as
the Wellesley used?
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PMN1 |
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Posts: 20 (04/01/09 12:43:12) |
The B-50 introduced two wing pylons each able to carry a 700 gallon fuel tank (or a 4,000lb bomb).
Could earlier aircraft such as the Stirling, Sunderland, B-24, Halifax, Lancaster etc have been fitted with large external tanks and if so would the extra drag etc have outweighed any advantage in the extra fuel? I'm not thinking for ETO bombing missions, more Atlantic VLR and Indian Ocean/Pacific Ocean operations.
'We are showing progress. Things are getting worse at a slower rate'
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Roller007 |
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Posts: 941 (04/01/09 18:36:34) Uncle Sam
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The B-24 and B-17 had optional external tanks but any extra fuel came at a cost of weapons load or armour. The B-24's the RAF used in India and Burma were
cut down to next to nothing and carried some impressive loads of fuel and bombs quite far.
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PMN1 |
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Posts: 21 (04/23/09 13:04:43) |
According to U-boat.net, the Mk24 FIDO was designed to fit a 1,000lb bomb rack (max size 19" x 90"), given the Stirling was designed to carry 2,000lb
AP bombs in its bomb cells, what kind of performance could you expect from a torpedo designed around that (or indeed a Halifax MPA, bomb bay)?
Would you want a bigger torpedo? Edit, what was the diameter of the 2,000lb AP bomb?
'We are showing progress. Things are getting worse at a slower rate'
Last Edited By: PMN1
04/23/09 13:24:38.
Edited 1 times.
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Roller007 |
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Posts: 984 (05/15/09 08:39:30) Uncle Sam
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Thant's what I'm trying to find out. GP's are easy but the AP ones vary depending on US and UK and so on.
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PMN1 |
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Posts: 31 (06/27/09 05:27:40) |
The Martin Mariner carried its weapons load in extended engine nacelles, could the aircraft types that were historically used for MR be fitted with extended
nacelles to get the spread you are looking for with the Stirling's wing cells?
'We are showing progress. Things are getting worse at a slower rate'
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Roller007 |
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Posts: 1013 (06/30/09 10:18:26) Uncle Sam
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I'm sure if there is a will there's a way.
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vpsoccer |
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Posts: 32 (06/30/09 15:03:40) Now psoccer
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Problem is centre of gravity.
AIUI, your payload needs to be more-or-less in line with the CoG. |
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The Argus |
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Posts: 360 (07/22/09 06:09:13) Umpire |
DC 250lb Mk.VIII (Obsolescent) <note 1946 data>
Fusing - Hydrostatic Tail Pistols Mks.XIV, XIV*, XVI, XVI or Mk.XX** Colour Markings - Dark Green overall, 1/2 inch red band around nose, 2 inch light green cross hatched band near suspension lugs Tail No. - N/A Overall Length - 56 inches Body Length - 38.15 inches Body Diameter - 11 inches Wall Thickness - N/A Tail Length - 17.8 inches Tail Width - 11 inches Total Weight - 265lb (Amatol filled) Charge/Weight - 66% DC 250lb Mk.IX & IX* (Service) Fusing - Hydrostatic Tail Pistols Mks.XIV, XVI, XIX or Mk.XX Colour Markings - Dark Green overall, 1/2 inch red band around nose with coloured band to indicate filling in front of suspension lugs Tail No. - Mk.III, Mk.IV with Pistols Mk.XIX & XX Overall Length - 54.8 inches Body Length - 37 inches Body Diameter - 11 inches Wall Thickness - N/A Tail Length - 17.8 inches Tail Width - 11 inches Total Weight - 265lb Charge/Weight - 66% AS 600lb Mk.I Fusing - Tail Fuse No.862 Colour Markings - Dark Green overall, 1/2 inch red band and 1 inch light green band around body Tail No. - No.36 Mk.I Overall Length - 56.7 inches Body Length - 36 inches (without nose attachment) Body Diameter - 17.5 inches Wall Thickness - 0.125 inches Tail Length - 20.5 inches Tail Width - 17.5 inches Total Weight - 550lb Charge/Weight - 80% GP 250lb Mk.IV Fusing -Nose Pistol, No.27, 42 or 44. Tail Pistol No.28, 30 or 37 Tail No. - No.2 Mk.II Overall Length - 56 inches Body Length - 25.6 inches Body Diameter - 10.2 inches Wall Thickness - 0.52 inches Tail Length - 27.7 inches Tail Width - 10.2 inches Total Weight - 230lb Charge/Weight - 29% GP 500lb Mk.IV Fusing -Nose Pistol, No.27, 42 or 44. Tail Pistol No.28, 30 or 37 Tail No. - No.2 Mk.II, No.26 Mk.I or II Overall Length - No.2 Tail, 70.6 inches, No.26 Tail 55.5 inches Body Length - 37.2 inches Body Diameter - 12.9 inches Wall Thickness - 0.72 inches Tail Length - No.2 Mk.1 33.4 inches, No.26 20.4 inches Tail Width - 12.9 inches Total Weight - 470lb with No.2 Tail Charge/Weight - 31% GP 1000lb Mk.I-IV Fusing - Mks.I & II, Nose Pistol, No.27, 42 or 44. Tail Pistol No.28, 30 or 37. Mks.III & IV Tail Pistol No.28, 30 or 37 Tail No. - No.13 Mk.I, No.29 Mk.I Overall Length - No.13 Tail, 86.5 inches. No.29 Tail 71 inches Body Length - 52.5 inches Body Diameter - 16.15 inches Wall Thickness - 0.77 inches Tail Length - No.13 Mk.I 35.5 inches, No.29 20.4 inches Tail Width - 16 inches Total Weight - 1,072lb with No.29 Tail Charge/Weight - 33% GP 1900lb Mk.I & II (Service) Fusing - Nose Pistol, No.27, 42 or 44. Tail Pistol No.28, 30 or 37 Tail No. - No.14 Mk.I Overall Length - 98 inches Body Length - 63.2 inches Body Diameter - 18.7 inches Wall Thickness - 1.15 inches Tail Length - 35.3 inches Tail Width - 18.7 inches Total Weight - 1,785lb Charge/Weight - 26% GP 4000lb Mk.I & II (Service) Fusing - Nose Pistol, No.27, 42 or 44. Tail Pistol No.28, 30 or 37 Tail No. - No.34 Mk.I Overall Length - 106.5 inches Body Length - 79.3 inches Body Diameter - 24.5 inches Wall Thickness - 1.35 inches Tail Length - 23.5 inches Tail Width - N/A Total Weight - 3,587lb Charge/Weight - 30% MC 1000lb Mk.I & II (Service) Fusing - Nose Pistol, No.27, 42 or 44. Tail Pistol No.28, 30 or 37 Tail No. - No.37 Mk.I Overall Length - 72.6 inches Body Length - 52.5 inches Body Diameter - 17.75 inches Wall Thickness - 0.48 inches Tail Length - 20 inches Tail Width - 17.5 inches Total Weight - 1,021lb (Amatol filled) Charge/Weight - 47% MC 4000lb Mk.I & II (Service) Fusing - Nose Pistol, No.27, 42 or 44. Tail Pistol No.28, 30 or 37 Tail No. - No.38 Mk.I Overall Length - 109.5 inches Body Length - 74.5 inches Body Diameter - 30 inches Wall Thickness - 0.75 inches Tail Length - 33 inches Tail Width - 30 inches Total Weight - 3,764lb (Amatol filled) Charge/Weight - 58% AP 2000lb Mk.I, II, III & IV (Service) Fusing - Mks. I, II & III Tail Pistol No.28, 30 or 37. Mk.IV, Tail Pistol No.30 only Tail No. - Mk.I, No.1 Mk.I, Mks.II & III, No.10 Mk.I. Mk.IV, No.47 Mk.I Overall Length - 113 inches Body Length - 80 inches Body Diameter - 13.5 inches Wall Thickness - 2.4 inches approx Tail Length - 35.5 inches Tail Width - 13.5 inches Total Weight - 1,934lb (Amatol filled) Charge/Weight - 9% HC 2000lb Mk.II & III (Service) Fusing - Mk.II, Nose Pistols 27, 42 or 44. Mk.III, fitted with three Nose Pistols 27, 42 or 44 Tail No. - No.39 Mk.I Overall Length - 131 inches Body Length - 89 inches Body Diameter - 18.5 inches Wall Thickness - 0.19 inches approx Tail Length - 40 inches Tail Width - 17.9 inches Total Weight - 1,732lb Charge/Weight - 71% shane
Rule .303
Shoot straight, you bastards.
Last Edited By: The Argus
07/22/09 06:11:20.
Edited 1 times.
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