Author Topic: Apophenia's Offerings  (Read 560880 times)

Offline Logan Hartke

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Re: Apophenia's Offerings
« Reply #2775 on: August 05, 2021, 08:46:47 AM »
Glad I could inspire a few of your works, apophenia! I know plenty have gone in the other direction!

You could also look at something like the 8x8 Ratel Logistics variant.



I always thought that looked pretty sharp, too.

Offline apophenia

  • Patterns? What patterns?
Re: Apophenia's Offerings
« Reply #2776 on: August 05, 2021, 10:37:50 AM »
I do like that Ratel LOG  :smiley:

Compared with my approach, that was also probably a much simpler route, mechanically, for getting to an 8x8 Ratel!

I was trying to get the turrets over the rear axles (although my Ratel 122 probably needs stabilizing jacks too). Since the RW Ratel 90 could manage a forward placed turret, maybe a mid-placed T-55 turret would be okay (except maybe on soft ground?).

And speaking of the Ratel 90 ... here a quickie of a shortie  ;D
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Offline Logan Hartke

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Re: Apophenia's Offerings
« Reply #2777 on: August 05, 2021, 11:57:05 AM »
That short Ratel 90 looks a lot like a VAB Mk 3.



I went with the mid-mounted turret on the Ratel 6x6 so I could grab a standard vehicle off the line and it shouldn’t need any modifications to the lower hull or powertrain to accommodate the T-34 turret.

I thought about an 8x8 with a T-54/55 turret, but then I figured I would probably just make it look like the Ratel-based Concept 1 pre-Rooikat developmental prototype, but with the turrets swapped (which, for the record, I still think would be viable).



I like the Concept 2 and 3 vehicles a little more aesthetically because of their lower silhouette and I think the Rooikat itself is downright sexy, but a Ratel-based vehicle is the only sensible option for the early-80s SADF, logistically speaking. And I don’t think the Concept 1 looks bad, certainly still looks modern today, over 40 years later.

Offline apophenia

  • Patterns? What patterns?
Re: Apophenia's Offerings
« Reply #2778 on: August 06, 2021, 06:38:21 AM »
I went with the mid-mounted turret on the Ratel 6x6 so I could grab a standard vehicle off the line and it shouldn’t need any modifications to the lower hull or powertrain to accommodate the T-34 turret...

Very wise. I was well aware of the irony of rearranging drive components on a vehicle explicitly intended to use COTS drivetrain parts! Fortunately, development budgets can be infinitely expandable in whif-world  ;D

Agreed too on the merits of the Rooikat. Doubtless, RW SADF experience with the Ratel and 'Noddy Car' during Operations Savannah and Reindeer drove the requirement leading to Rooikat.
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Offline apophenia

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Re: Apophenia's Offerings
« Reply #2779 on: August 08, 2021, 10:21:15 AM »
I decided that I can't justify squeezing this into the 1920s/1930s GB or Between the Wars GB thread. It is part of the  PZL fighter sequence from that GB but there's too much September 1939 content. So ...
_________________________________

The PZL.51 was considered the definitive production variant of the PZL.41 Krogulec II (Sparrowhawk II). The key difference between the PZL.41 and PZL.51a was the latter's totally new main landing gear arrangement. Referred to as the 'typ Curtiss', this undercarriage was a licensed copy of the gear on the Curtiss Hawk 75A fighter. [1] This landing gear retracted aft but also turned 90° to lie flat with the wheels housed within the wings. Fairings were still required for the legs themselves and retraction gear but the drag-inducing 'kajaki' ('canoes') of the PZL.41 could be dispensed with.

Initially, the Polish air force had been reluctant to accept another change on PZL's WP-1 production line. Accordingly, an early-model PZL.31 Krogulec airframe had been rebuilt with the 'typ Curtiss' gear as a private venture. Once superior performance was demonstrated, the new type was ordered as the P.51a. To distinguish this further revised fighter from the PZL.41 Krogulec II, the P.51 received the name Kosmacz (Rough-Legged Hawk). Few other changes were introduced to simply the production line change over. A minor but distinctive change was the introduction of aft cockpit glazing in an attempt to improve rearward vision.

The P.51a retained the 4-gun armament of the PZL.41b - with one 7.9 mm wz.33 machine gun in either wing and on both sides of the fuselage. With the 20 mm Oerlikon FFS cannon previously eliminated for reasons of cost, the P.51b was to be armed with six wz.33 guns - with two mounted in each wing. The P.51B designation may seem to be a duplicate of the unbuilt P.51b, but it wasn't. Instead, the P.51B (for 'typ Bristolski') was an experimental machine converted to compare modern British cowling designs to their Polish opposites.

Bottom The PZL.51B Kosmacz experimental aircraft which trialed the 'typ Bristolski' cowling. On the first of September 1939, this aircraft (serial 14.168) was impressed to defend the Warsaw-Okęcie plant and surrounded areas. Like many frontline Polish fighters, finish is wzór kamuflaźu 38 (Camouflage Pattern 1938).

Wzór kamuflaźu 38 consisted of a German-influenced three-colour splinter pattern - made up of a relatively uniform scheme - for fighters - of khaki ciemny (Dark Khaki), zielona trawa (Grass Green), and beźowy (Beige) over jasny niebieski (Light Blue). [2]

The PZL.51B is depicted as it might have appeared on 02 September. Note that 14.168 did not have wireless equipment fitted. It is possible that wing guns were not fitted while on trials either. Also note that ground crews have overpainted the fuselage side PZL logo during the night of 01/02 September. While flying this aircraft, PZL test pilot Stanisław Riess claimed one Luftwaffe Do 17E and two He 111Ps damaged.

PZL.61 Kania - the Ultimate PZL Fighter of World War Two

In late August 1939, the revised PZL.61 fighter began reaching Polish squadrons. The development process had been a long one. Although closely related to the P.51 Kosmacz, the PZL.61 introduced two key changes. The first was a twin-row radial engine. The second was a lengthened fuselage to cope with that longer, heavier engine. In the initial plans, the P.61a was to be powered by the new PZL Smok (Dragon) twin-row radial. [3] Displacing 38.67 litres, the Smok was to generated 1,100 hp for take-off. This engine was, in effect, a Gnome-Rhône 14K crankcase revised to accept Bristol Mercury cylinders. Unfortunately, Smok prototypes suffered from severe overheating on the test bench and their was no sign of a quick cure.

The proposed cannon-armed PZL.61b was skipped over in favour of two variants powered by imported engines. The PZL.61c was a PZL.61a airframe fitted with a 930 hp Romanian-built IAR 14K powerplant. [4] This was a comparatively easy fit since the IAR K14-I C32 engine was being built for the IAR-built PZL P.24E fighter. Records are now lost but it appears that between 12 and 16 PZL.61c fighters were completed and delivered before the outbreak of war. Most PZL.61cs went to the fighter squadrons at Lwów but a few went straight from the Okęcie to local squadrons for the defence of Warsaw.

The name Kania was given to the PZL.61 series to distinguish this new fighter from the less-powerful PZL.51 Kosmacz. [5]

Top A six-gunned PZL.61c Kania (14.187) [6] in service with the 162. Eskadra Myśliwska for the defence of Lwów. These aircraft replaced PZL P.7a and interim P.31 fighters. Like his squadron makes, Podporucznik (2nd Lt) Czesław Główczyński had only days to adjust to the PZL.61c before being committed to combat. Having scored four aerial victories, ppor. Główczyński flew his aircraft across the Romanian border on 17 September 1939. With other 162.EM survivors, Główczyński made his way into exile - first in France, then in Britain.

_____________________________

[1] In fact, the patent for this 'typ Curtiss' undercarriage actually belonged to the Boeing Airplane Company.

[2] Wzór kamuflaźu 38 varied slightly depending on the intended role of the aircraft it was applied to. Light bombers and ground-attack aircraft, for example, generally received pl/owy brąz (Tawny Brown - a darker, reddish tone) rather than the tan/beige beźowy. In cases of last-moment overpainting, the old khaki średni (Medium Khaki) was left exposed rather than applying the new khaki ciemny. Such overpaints often left fuselage undersides in original colours as well - fresh applications of the greyish-blue jasny niebieski being a depot level job.

[3] The Smok appellation match other PZL engines in development. In size, the Smok was to fit between PZL's Waran (Goanna) and the Legwan (Iguana) engines.

[4] The IAR K14-I C32P (for Polonia) differed from Romania engines solely in having gun synchronization gear fitted. The unbuilt PZL.61d was to be fitted with a higher-powered Gnome-Rhône 14N radial but France was unable or unwilling to supply these engines.

[5] The name Kania had been reserved for Jakimiuk's earlier PZL.56 concept. This was basically a Hispano-Suiza 12Y-powered derivative of the abandoned PZL.50. However, difficulties in securing supplies of HS 12Y engines ended the PZL.56 programme.

[6] Note that the Polish air force assigned PZL.61 Kanias serials in the same sequence as the P.51 Kosmaczs.

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Offline Gingie

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Re: Apophenia's Offerings
« Reply #2780 on: August 10, 2021, 12:41:46 AM »
Really digging your Swede ideas. Hmm.

Offline apophenia

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Re: Apophenia's Offerings
« Reply #2781 on: August 10, 2021, 02:24:23 AM »
Really digging your Swede ideas. Hmm.

Thanks Graeme  :smiley:  I like those recycling/renewal ideas with brand-new replacements hot-on-the-heels.

I'm not really sure if that approach would represent good economy in the RW. Still, folks like the Swedes and Israelis come up with some seriously cool adaptions  :D

Speaking of Swedes, have you been following Ramba's Strv 103C recce vehicle adaptation?
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Offline Old Wombat

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Re: Apophenia's Offerings
« Reply #2782 on: August 10, 2021, 09:24:18 PM »
Speaking of Swedes, have you been following Ramba's Strv 103C recce vehicle adaptation?

I have! 8)
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Offline apophenia

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Re: Apophenia's Offerings
« Reply #2783 on: August 16, 2021, 09:54:17 AM »
One for the rivet-counters ...

Nuffield Mechanizations Ltd A13 Mark III (Cruiser, Reconnaissance, Mk.I)

The 'A13R' Cavalier was a fast reconnaissance tank based upon the failed Nuffield A13 Mark I (Cruiser Mk.III) prototype (A13E1). Nuffields had intended to power the A13 series with license-built Liberty L-12 aero engines. However, the reliability issues with this US engine and the excessive weight of the A13 prototype put paid to that plan. Baron Nuffield was forced to send his Birmingham design team back to the drawing board.

With component production already underway, an engine change promised both weight reduction and superior maintenance characteristics. The proposed engine was the result of work already underway between Rolls-Royce and Nuffields. [1] Greatest importance had been assigned to development of the Rolls-Royce Rail V-12 - an unsupercharged Kestrel adapted for land-use. But priority was quickly shifted from the V-12 to a V-8 derivative - the Rolls-Royce Rhea. [2]

Image Recce Cruiser - a Nuffield 'A13R' Cavalier of the 1st armoured Division, British Expeditionary Force, France, May 1940. This vehicle was sabotaged and abandoned outside of Dunkirk on 03 June 1940.

(To be continued ...)

___________________________

[1] Relations with Rolls-Royce warmed after William Morris (later Viscount Nuffield) abandoned his plans for aero engine production. In a co-development agreement, overall design control remained with Rolls-Royce while production of 'land-use' engines would be performed by Nuffields.

[2] The V-12 Rail had been intended for Nuffield's A16E1 Heavy Cruiser project. A teritiary prioity was the Roadrunner series of 4- and -6-cylinder engines for light armoured vehicles.
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Offline apophenia

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Re: Apophenia's Offerings
« Reply #2784 on: August 20, 2021, 05:48:13 AM »
Keeping Up With the Joneses - the 'Nuffield Carrier'

The Carrier, Cruiser was designed alongside the A13 Cruiser Mk.III tank. The object was to produce a support vehicle which could keep pace with the quicker A13 tanks. When the Cruiser Mk.III was dropped in favour of the producing the 'A13R' Cavalier fast reconnaissance tank (see previous post), the Carrier, Cruiser lost its priority. But the 'Nuffield Carrier' was seen as having potential utility of its own. Once 'A13R' production was underway, design work recommenced on the Carrier, Cruiser.

In keeping with the original concept, the Carrier, Cruiser used the roadwheels and suspension of Nuffields' Cruiser tank. The drivetrain differed in having front drive sprockets and a smaller, more fuel-efficient engine was employed. The latter was a 96 hp Morris 6-cylinder taken from the Morris Commercial C9 lorry. [1] The narrow Morris 6-cylinder fit alongside the driver, freeing the rear compartment of all drivetrain components. But, this powerplant choice would also effect the future of the Carrier, Cruiser. The Morris produced only 10 hp more than the Universal Carrier's Ford V-8 motor. To maintain speed, Nuffields had to sacrifice armour protection.

As was common at the time, no overhead armour was used. In other locations, armour thickness varied from 6-to-14 mm (comparable with the Universal Carrier's 7-to-10 mm protection). In draughting the Carrier, Cruiser, Nuffields' design team pushed the upper body armour out over the tracks. Stowage space for spares and crew gear lined the inside of that upper armour plating. Although the plate was not thick, the design counted on this interior stowage to add a modicum of extra protection for the crew. That assumption would not be borne out in battle. In the Western Desert, it was found that carrying water containers in the stowage bins helped protect against small arms fire and shell splinters. However, the 'Nuffield Carriers' would always be vulnerable to larger-calibre weapons.

Top Carrier, Cruiser Mk.IA: Production variant with A9-style machine gun turret. [2] The driver's position, engine compartment, and  rear carrier space remained uncovered. This vehicle has had a swivel-mounted Lewis gun added to its armament.

Bottom Carrier, Cruiser Mk.III: Although not intended as a gun carrier, [3] this vehicle has been armed with a captured Italian Breda 20/65 20mm cannon for anti-aircraft use. A Lewis gun mount has been added just behind the driver's position. Oddly, this 'sand-and-stone' Mk.III has not be fitted with the larger 'sand skirts' which were becoming standard kit in North Africa.

(To be continued ...)
______________________________________

[1] This engine would also power the Morris-built CS9 armoured car.

[2] The Carrier, Cruiser Mk.IA was the first real production type - the pre-production Mk.Is with its exposed Bren gun in 360° swivel mount was seen as unworkable (with most becoming Cruiser Gun Tractors).

[3] The Mk.III was meant to be a straighter Carrier version of the more heavily-armed Carrier, Cruiser Mk.II. However, even with gun mount shields installed, the Mk.II's gun positions were regarded as highly vulnerable in combat.
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Offline GTX_Admin

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Re: Apophenia's Offerings
« Reply #2785 on: August 21, 2021, 02:12:25 AM »
Interesting...
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Offline jcf

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Re: Apophenia's Offerings
« Reply #2786 on: August 21, 2021, 04:16:15 AM »
 :smiley: :smiley:

Very nice, gives rise to thoughts of a Christie wheel n' track carrier/APC.
“Conspiracy theory’s got to be simple.
Sense doesn’t come into it. People are
more scared of how complicated shit
actually is than they ever are about
whatever’s supposed to be behind the
conspiracy.”
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Offline Buzzbomb

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Re: Apophenia's Offerings
« Reply #2787 on: August 21, 2021, 08:09:49 AM »
Oh... that is Gold !!!!!
What great thinking. I think you have just ignited the spark of inspiration.

Offline apophenia

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Re: Apophenia's Offerings
« Reply #2788 on: August 21, 2021, 10:21:57 AM »
Thanks folks! But wait, there's more ...
_______________________________

When the A16E1 Heavy Cruiser prototype was cancelled, the Nuffield design team returned to standard Cruiser design - the object was a potential replacement for the in-service A9 and A10 fleets. A development contract had already been given to the rival London, Midland and Scottish Railway. The LMS's more heavily-armoured, A13R-based Covenanter tank should have been a winner. But Nuffields had their doubts about the untested Meadows powerplant - consisting of an entirely new, 340 hp Meadows D.A.V HO-12 petrol engine and a gearbox using Major Wilson's planetary steering. Nuffields had more faith in the slightly less powerful Rhea V-8 from the A13R.

Dubbed the A13M, the Nuffield Cruiser design strongly resembled the LMS Covenanter - the latter's turret having been designed by Nuffields. Where the Covenanter had forward hull radiators, the A13M featured a single, A9-style machine gun turret. In other respects, the A13M strongly resembled the original A13E1 prototype. Before planned A13M production could commence, combat reports from North Africa prompted a major redesign. A new emphasis would be placed on armour protection - especially in the front quadrant. This shifted weight in a way that would demand a near complete revision of the A13M design. The changes were significant enough to warrant a new designation - as the A15 Crusader.

Evolving the 'Christie Cruiser' - On to the A15 Crusader

Knowing that the redesigned Cruiser would have increased weight prompted a return to the A16E1's more powerful Rolls-Royce Rail V-12 engine. Although  an untested type, the Rail was based on the well-proven Rolls-Royce Kestrel aero-engine and had a great deal of commonality with the less powerful Rhea V-8 of the 'A13R'. The physically-longer Rail V-12 resulted in a five roadwheel arrangement to better balance the increased weight. The A13M's machine gun turret was ditched and the driver's position moved slightly. This shifted the c/g aft allowing for heavier bow armour and a well-sloped glacis plate. The turret front armour was also thickened. Other introduced changes reflected features of the then-most successful tank in the Western Desert - the German Panzer Mark III. The most obvious German influences being in the style of the gun mantlet and commander's cupola.

Despite its erratic start, the A15 Crusader was highly promising. However, there were disappointments. The tank had been designed for a 6-pounder main armament but that gun was delayed. Instead, the old 2-pounder was installed - a gun already outclassed by the 5 cm (1.97 inch) cannon in Afrika Korps tanks. But it got worse. The Germans were now introducing a higher-velocity 5 cm KwK 39 L/60 tank gun firing 5-pound AP shells. Being forced to retain the 2-pounder, the A15 Crusader Mk.Is and Mk.IAs handed the gun battle advantage to the newest Panzer Mark IIIs with longer cannons. When the Crusader Mk.IIs finally arrived armed with 6-pounders, they also featured thicker turret front armour. Both features were very welcome but the extra weight also made these vehicles slightly nose-heavy. However, the balance in North African tank battles had been re-established. For now ...

(To be continued ...)
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Offline apophenia

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Re: Apophenia's Offerings
« Reply #2789 on: August 24, 2021, 07:51:45 AM »
Nuffield A15 Gun Carriers

Nuffields' design team had sketched the layout for a close-support gun carrier to accompany its original A13 Cruiser tank design. That concept was revived for the A15 Crusader series when it was realized that the longer A15 hull could better cope with the gun carrier's inherent nose-heaviness. An opportunity to pursue the close-support design arose when a turretless A15 driving trainer prototype was returned to Nuffields. As a demonstrator, staff at the Ward End plant in Birmingham devised a simple, open fighting compartment intended to accommodate a range of artillery pieces for the direct-fire close-support role.

In the initial plan, a surplus 18-pounder field gun was envisioned. However, reports from North Africa suggested than a higher-velocity gun would soon be required. Accordingly, a 25-year-old QF 13 pounder 9 cwt anti-aircraft gun was adopted instead. This WWI piece was effectively an 18-pounder sleeved with a liner to fire smaller-diameter 3-inch shells. [1] As a result, all that was required was some reinforcement of the original gun mount design.  The short-barrelled (L/31) QF 13 pounder 9 cwt fired a 12.5 lb shell with a muzzle velocity of 2,150 ft/s. This compared very well with another L/31 tank gun about to enter service - the US M2 mounted in American-made Lee and Grant medium tanks. [2]

The prototype Nuffield A15CS (Close Support) Gun Carrier received a well-worn, 1918-vintage QF 13 pounder 9 cwt from storage. Despite its age the gun performed well and the downsides of its short barrel were offset by the reasonably good balance of the vehicle. However, the official review of the prototype found multiple faults - primarily in the design of the fighting compartment. The cramped conditions were a by-product of the original A15 hull design (in turn, dictated by British railway tunnel size). The open-topped fighting compartment - adopted to save weight - was also seen as excessively vulnerable to shell splinters for 'close-in' work. There was also doubt about whether such a vehicle was needed. Heavier Churchill tanks were already being fitted with howitzers to fill the close support role. The A15CS seemed redundant. For the time being, the A15CS was disarmed and pushed into a corner at Ward End.

Hard Slog - the Nuffield A15M Artemis 3-inch Gun Carrier

In North Africa, deploying the 6-pounder armed A15 Crusader Mk.II Cruiser tank took the advantage away from the Afrika Korps' long-gunned Panzer Mark IIIs. Unfortunately, a literally bigger threat was emerging. In 1942, the Germans introduced long guns on their larger Panzer Mark IVs. The stumpy, close-support 75 gave way for a new 7.5 cm KwK 40 L/43 high-velocity gun. Once again, the Desert Rats found themselves outmatched. The long-gunned Panzer Mark III remained a deadly opponent, but this new version of Panzer Mark IV dominated the battlefield. The arrival of US-made Grant medium tanks armed with L/31 M2 guns helped but those sponson-mounted and relatively low-velocity 75s were still outperformed by the longer-barrelled 7.5 cm KwK 40s.

In the background, Vickers had been working on a new 75 mm L/50 High Velocity (HV) tank gun. This new gun was to use a necked-down version of the 76.2 x 420R cartridge from the older QF 3-inch 20 cwt anti-aircraft gun. The projectiles would be the same 14 lb shells fired by US M2 sponson guns. However, with a 50-calibres length barrel the Vickers gun would have a higher velocity than the L/31 barrels on the Grant's M2. The Vickers gun was highly promising but 'productionizing' such guns would take time. As a concept demonstrator, Vickers was asked to convert a number of WWI-era QF 3-inch 20 cwt tubes for armoured vehicle use. [3] The result was the QF 3-inch L/45 HV gun. One such demonstrator piece was mounted experimentally in the former A15CS Gun Carrier hull. The 11-foot barrel of the QF 3-inch L/45 HV was deleterious to balance and vehicle handling but its firepower was impressive.

The production version of the revised A15CS Gun Carrier was the A15M Artemis aka 3-inch Gun Carrier. These vehicles used unmodified A15 Crusader hulls fitted with a roofed version of the A15CS Gun Carrier's casement replacing the turret and upper glacis plate. Pending availability of 75 mm guns, the QF 3-inch L/45 HV piece was retained. As the ad hoc arrangement that the A15M Artemis 3-inch Gun Carrier was, it would normally have become a footnote to history and quickly forgotten. But the Artemis deployed to North Africa at around the same time as the German's formidable new Tiger heavy tank. The only Allied vehicle with a change of defeating the Tiger was the A15M with its high-velocity 3-inch gun.

(To be continued ...)
_____________________________________

[1] This liner sleeve also served strengthen the wire-wound barrel of the original 18 pounder.

[2] The QF 13 pounder 9 cwt used a 76.2 x 295R shell - effectively an 18-pounder round necked-down to take a 13-pounder shell. The inserted sleeve reduced the bore from 3.3-inches (84 mm) to 3-inches (76.2 mm). By comparison, the American 75 mm cartridge was a 75 x 350 fired at 1,850 ft/s by the L/21 M2 gun.

[3] The QF 3-inch 20 cwt guns were still operating as back-ups in the anti-aircraft role. However, a number of stored gun systems were found to be lacking predictors and other equipment essential for AA work. These pieces were singled out for conversion to QF 3-inch L/45 HV status.
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Offline jcf

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Re: Apophenia's Offerings
« Reply #2790 on: August 26, 2021, 01:42:23 AM »
 :smiley: :smiley:

George Eyston's endurance car Speed of the Wind was Kestrel powered, but it was also
run with a diesel under the name Flying Spray.
The engine used in the diesel configuration was a Kestrel-based sleeve-valve engine designed
by Harry Ricardo.


British engineer Harry Ricardo had built a diesel, sleeve-valve version of the Kestrel.
Known as the RR/D (Rolls-Royce/Diesel) or Ricardo Diesel. The engine could be fitted to Speed of the Wind
with only minor modifications. Compared to the Kestrel, the Ricardo Diesel’s bore was decreased by .25 in (6.35 mm)
to 4.75 in (121 mm). This provided room for the single sleeve valve around each cylinder. The sleeve valves were
driven from the rear of the engine by a gearset that ran along the outer side of each cylinder bank. A new cylinder
featured a vortex-type combustion chamber with a fuel injector positioned vertically atop the chamber. The Ricardo
Diesel displaced 1,170 cu in (19.2 L) and produced 340 hp (254 kW) at 2,400 rpm.

- Note the exposed sleeve-valve drive geartrain running along the side of the crankcase below the cylinder block.


Flying Spray at Bonneville 1936.

https://oldmachinepress.com/2020/03/20/eyston-eldridge-speed-of-the-wind-flying-spray/

Perhaps a diesel A15 would have resulted.  ;)
« Last Edit: August 26, 2021, 03:44:06 PM by jcf »
“Conspiracy theory’s got to be simple.
Sense doesn’t come into it. People are
more scared of how complicated shit
actually is than they ever are about
whatever’s supposed to be behind the
conspiracy.”
-The Peripheral, William Gibson 2014

Offline apophenia

  • Patterns? What patterns?
Re: Apophenia's Offerings
« Reply #2791 on: August 26, 2021, 06:39:35 AM »
... Perhaps a diesel A15 would have resiulted.  ;)

You have anticipated me Jon!  I'd actually written a whole storyline about Ricardo's Kestrel-based diesel but it got excised (for what passes for terseness with me)  ;D

Buuuut, it isn't the A15 (or any direct derivative) that gets the diesel  ;)

Actually, the RR/D was something of a prompt for this whole Nuffield story. With the Kestrel and Ricardo Diesel around, why was William Morris faffing about with Liberty 12s? Good engine but the Kestrel was a generation younger!
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Offline ChernayaAkula

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Re: Apophenia's Offerings
« Reply #2792 on: August 26, 2021, 12:31:07 PM »
Really liking those Crusaders.  :smiley:
Might be a handy excuse to get one of Tamiya's 1/48 Crusaders. I've got this hypothesis that 1/48 may actually be the ideal scale for armour modelling, marking a sweet spot between (too?) small 1/72 and (too?) big 1/35.
Cheers,
Moritz

"The appropriate response to reality is to go insane!"

Offline apophenia

  • Patterns? What patterns?
Re: Apophenia's Offerings
« Reply #2793 on: August 27, 2021, 02:29:19 AM »
Thanks Moritz! I have one more Crusader(ish) vehicle to mount before moving on to bigger tanks ... where 1/48 really could save on shelf space  ;)
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Offline apophenia

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Re: Apophenia's Offerings
« Reply #2794 on: August 27, 2021, 10:29:59 AM »
Carrier Update - the A15-Based Nuffield Weapons Carrier

The A13R-based 'Nuffield Carrier' never quite lived up to its promise. Supply problems with Morris 6-cylinder engines [1] were solved by substituting the slightly more powerful Gardner 6-cylinder diesel. Ready availability from L. Gardner and Sons was key. The additional 8 hp was undetectable although the diesel's higher torque levels was useful. However, there was no helping the Nuffield Carrier's flimsy armour protection. Fortunately, work was already underway on a replacement vehicle.

Although it had a strong family resemblance to the earlier Nuffield Carrier, Nuffield's Weapons Carrier was a completely different vehicle. The Weapons Carrier made use of A15 Crusader suspension units. Armour protection was improved and the discredited 'stowage armour' concept was abandoned. Armour thickness almost doubled - increased to 12-to-22 mm thick (up from 6-to-14 mm). Other than being based on the A15 Crusader suspension, the new vehicle retained the general drivetrain layout of the Nuffield Carrier. However, the small Gardner engine was replaced with a much more powerful diesel. Rolls-Royce's Roadrunner was an inline 6-cylinder development of the RR/D (Rolls-Royce/Diesel) - Harry Ricardo's prewar Kestrel diesel derivative. [2]

At 195 hp, the Nuffield-built Rolls-Royce Roadrunner was almost twice as powerful as its predecessor. As a result, the new Weapons Carrier was faster than the earlier Nuffield Carrier while also being better-protected. Had the Weapons Carrier been available at the outset of the war, it probably would have seen much wider service. But, as it was, many of the Weapons Carrier's intended roles were already being handled by smaller, if less-capable, Universal Carriers. Other planned roles -  gun tugs and artillery spotting - were taken over by Nuffield's A15GT Culverin Gun Tractor (see below).

Despite its rather generic name, Nuffield's Weapons Carrier was rarely used as a simple gun carrier - that remained he job of the Universal 'Bren Gun Carriers'. Instead, the Weapons Carriers were assigned specialist roles. A major Weapons Carrier role was as a machine gun troop Platoon Commander’s Carrier. As a 'PCC', the Weapons Carrier housed three wireless sets - one short-range HF Wireless Set No.22 (later No.62) and two 'manpack' type Wireless Set No.31s. Vehicle protection was provided by one (or two) pintle-mounted Bren light machine guns.

However, the Nuffield Weapons Carrier is now best remembered as a mount for the Ordnance ML 4.2-inch mortar. While the Universal Carrier was used as both a 3-inch mortar mount and a tow vehicle for the 4.2-inch, the Universal was too small to carry the heavy mortar. The first self-propelled mount for this mortar was the Weapons Carrier, 4.2-inch Mortar Mk.I. A rotary mount was provided, allowing the mortar to be fired facing forward or aft (for shoot-and-scoot firing). Most Ordnance ML 4.2-inch mortars remained towed pieces but the Weapons Carrier, 4.2-inch Mortar Mk.Is and Mk.IAs offered obvious mobility advantages where speed of deployment was vital and mortar emplacement was not needed.

Have Gun, Will Travel - the A15GT Culverin Gun Tractor

The A15GT Culverin Gun Tractor came about as a result of the unexpected success of Nuffield's A15M Artemis in the gun tug role. When it was decided not to re-arm the Artemis with new Vickers 75 mm HV guns, some A15Ms were field-modified with US M2 75s recovered from the battlefield. Other Artemis simply had their worn-out 3-inch guns removed and tow hitches fitted for use as artillery tractors. These ad hoc gun tug conversions worked surprisingly well but they were always few in number. Nuffield received inquiries from the Royal Artillery about producing new-production Artemis gun tugs.

The problem was that production of A15 hulls was winding down at Ward End. So too was assembly of Rolls-Royce Rail V-12s. In response to the RA's query, Nuffields proposed a new vehicle based upon a slightly stretched A15 hull to be powered by the related Rhea V-8. This engine was less powerful than the Rail but spare Rhea V-8s were available. The new gun tug would have a superstructure similar to that of the Artemis but, with V-8 engine fitted, the fighting compartment could now be made longer. This proposal was accepted and the A15GT Culverin Gun Tractor was produced at Ward End until stocks of A15 components and Rhea engines were exhausted.

Being well-protected the A15GT was popular with the gunners. Consideration was also given to producing a Mk.II ammunition carrier variant but this was never pursued. The Mk.IA variant had a more upright front plate - providing more interior space at the expense of a slight reduction in protection. The Culverin  Mk.III artillery spotter variant was only produced in small numbers. It differed most obviously from the gun tractors in being fully roofed.

(To be continued ...)
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[1] 'Nuffield Carrier' production had all but ceased after the Luftwaffe bombing of the Morris engine works at Courthouse Green. (And, once supplies of 96 hp Morris 6-cylinders resumed, wheeled gun tractors were given priority for these engines.) Small-scale 'Nuffield Carrier' production was resumed using Gardner diesels.

[2] In contrast with the 'Ricardo Diesel', the Roadrunner used tappet valves in place of Ricardo's sleeve valves. As a result the bore did not need to be reduced to fit the sleeve valve gearsets.
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Offline jcf

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Re: Apophenia's Offerings
« Reply #2795 on: August 28, 2021, 08:15:51 AM »
 :smiley:

Nice bit about the six-cylinder diesel.  :icon_fsm:

A Kestrel based 6 diesel would probably be a whole hell of a lot lighter than a GM
6-71 for a similar output, but I have to wonder about durability.
 ???
« Last Edit: August 28, 2021, 08:23:36 AM by jcf »
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Offline Buzzbomb

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Re: Apophenia's Offerings
« Reply #2796 on: August 28, 2021, 09:36:37 AM »
Loving your work.
Hitting right on a couple of my previous builds, so I am so pleased some of us think alike  :smiley: :smiley:


I have a junked Cromwell Models A9 Cruiser that obstinately refused to play nicely during the build phase, that may get a rerun with some of these ideas.
« Last Edit: August 28, 2021, 09:39:06 AM by Buzzbomb »

Offline apophenia

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Re: Apophenia's Offerings
« Reply #2797 on: August 29, 2021, 01:11:06 AM »
... A Kestrel based 6 diesel would probably be a whole hell of a lot lighter than a GM 6-71 for a similar output, but I have to wonder about durability...

Thanks Jon. My first thought was a Bedford-built 6-71. Actually, I'm puzzled as to why the 'Jimmy' wasn't built by GM affiliates abroad - especially in the UK. I have read that the coal lobby did all it could to discourage diesel use in Britain (but I don't know how true that is).

You're probably right about durability ... but I needed a Kestrel diesel derivative for what comes next  ;)

...I have a junked Cromwell Models A9 Cruiser that obstinately refused to play nicely ...

Brian: Love those builds! Your Nuffield 'Jagdpanzer' is gorgeous  :-*  And your Churchillian SP just says: "We're big, we're lumbering, and we'd probably destroy you even if we didn't want to ... but we really, really do want to!"

Looking forward to see what you come up with for your obstinate A9. Once I've wrapped up my Nuffield musings, I just have to have a go at an A9/A10 Cruiser-based carrier of some sort  :D
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Re: Apophenia's Offerings
« Reply #2798 on: August 29, 2021, 01:27:50 AM »
your Churchillian SP just says: "We're big, we're lumbering, and we'd probably destroy you even if we didn't want to ... but we really, really do want to!"


 ;D
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Offline apophenia

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Re: Apophenia's Offerings
« Reply #2799 on: August 30, 2021, 01:50:14 AM »
A34 Cossack - A Russo-British A15 Replacement

Under the Anglo-Soviet Military Supplies Agreement of 27 June 1942, Britain pledged to supply Stalin with armaments free of charge. This included British- and Canadian-made tanks (and other armoured vehicles). However, what the Red Army really needed in those dark days was increased numbers of their own, most-favoured T-34 medium tanks. Accordingly, an addenda to the June 1942 agreement made arrangements for T-34 plans and hardware samples to be provided to Britain to enable licensed T-34 production. As Nuffields had relevant Christie suspension experience, production of British T-34s was assigned to Ward End. But this production effort was not without its challenges.

In early October 1942, a sample T-34 hull arrived by rail at Birmingham having been shipped by Arctic Convoy from Archangelsk to Liverpool. Problems arose immediately. The early-model sample T-34 hull was essentially empty. Neither turret nor Kharkov V-2 diesel engine were included. Inquiries revealed that the Soviets would be unable to supply such items to Britain - the Red Army's immediate needs were simply too pressing. That left the design team at Ward End to their own devices. A quick study showed that the A15 turret would easily fit on the T-34. [2] Likewise, the Crusader's Rolls-Royce Rail V-12 and transmission fit the T-34 hull. However, the A15 turret was rejected as obsolete by the Soviets and, in reality, the 340 hp Rail lacked sufficient power for this heavier vehicle.

The solution to engine power proved relatively simple. Rolls-Royce informed Nuffields that, with supercharging, its Rail could easily match the Soviet diesel's output of 500 hp. That left the problems of turret and armament. The Matilda II's well-protected, cast turret fit but its 2-pounder (40 mm) armament was judged out-of-date. Fortunately, a larger turret with the same turret-ring size had just become available. This was the turret from the recently introduced Churchill Mk.III, armed with a high-velocity 6-pounder main gun. This weapon was of much smaller calibre than that Red Army T-34 guns - the 76 mm F-34s - but this was acceptable to the Soviets. [1] Shipments began of what the Red Army called the T-34 britanskiy birmingem. These 6-pounder armed T-34bb vehicles were adopted by the Red Army as tank-istrebiteli (or tank destroyers). [2]

Top An early Nuffield-built T-34 britanskiy birmingem in Red Army service as a tank destroyer, Spring 1943.

Once shipments of Nuffield-built T-34s were underway, the Director of the Royal Armoured Corps also expressed interest in the vehicle. Prior to export, some T-34s destined for the Soviet Union were successfuly tested at the RAC Centre at Bovington. As a result of these Dorset trials, the War Office requested transfer of some Nuffield T-34 production to the RAC under the designation A34 Cossack. The British Army knew the loaned T-34bb as the A34 Cossack Tank, Heavy Cruiser, Mark Is. The 'Anglicized' production variant was the A34 Cossack Mk.IA. The slightly later A34 Cossack Mk.IIA [4] was a purely experiment model - essentially a Mk.I hull fitted with the Raptor V-12 diesel engine from the T-34bd (Britanskiy dizel'. [3] This powertrain concept was then 'productionized' as the A34 Cossack Mk.III.

After the first British encounters with Germany's huge Tiger tanks, the pressure was on for up-gunned Cossacks. [5] The first in service was the A34 Cossack Mk.IVA armed with a Royal Ordnance QF 75 mm gun - a 6-pounder bored out to accept US 75 mm shells in 'necked' cartridges. The result was greater HE capacity shells but at much-reduced velocity (620 m/s - versus 1,082 m/s for 6-pounders firing APCR rounds). Other than in the calibre of its main gun and the design of ammunition stowage racks, the A34 Cossack Mk.IVA - being Raptor-engined - was virtually unchanged from the preceding, 6-pounder armed Mk.III. For the first time, the RAC was given priority on Cossack delivery. Only later would the Red Army receive QF 75 mm-armed A34 Cossack Mk.IVs built to Soviet standards.

The ultimate gun for the A34 Cossack series was the Vickers 75 mm L/50 HV. This piece also fired US 75 mm shells but from a much larger and more powerful cartridge. However, whereas the RO QF 75 mm fit within the A34's Churchill III turret, the bigger 75 mm L/50 HV would not. As a result, an entirely new turret was needed. At a glance, the turret of the A34 Cossack Mk.V looked like an extended A34 Mk.III turret. It wasn't. Sitting on a 'full-sized' 1,425 mm turret ring, the new turret was larger overall to accommodate the Vickers gun. [6] There were no Mk.V variants deliveries to the Soviet Union. Ward End production of the Mk.V was quickly eclipsed by the A34 Cossack Mk.VA which eliminated the bow machine gunner's position in favour of greater 75 mm ammunition stowage space.

Bottom Royal Tank Regiment A34 Cossack Mk.VA deployed in Normandy, July 1944. For greater protection, the crew of this otherwise near-pristine Cossack have welded tank tread sections (likely from a Churchill) to their turret sides. Note the Vickers-gunned tanks' distinguishing features - lengthy gun with muzzle brake, sloped mantlet, and longer turret rear 'bustle'.

(Fin)

___________________________________________

[1] The 6-pounder tank gun had a muzzle velocity of 892 m/s (with early armour-piercing rounds) versus only 680 m/s for the Soviet 76 mm F-34. Ideally, the T-34bb tank-istrebiteli and 76 mm-armed T-34s acted in concert. The T-34bb would be the dedicated 'hole puncher' while the T-34/76 performed the close-support role.

[2] In this role, the British-built vehicles made the Red Army's domestically-produced tank-istrebitel' - the T-34-57 - redundant. This allowed Soviet production to focus on 76 mm-gunned T-34s. However, some Nuffield tanks were rearmed locally with the T-34-57's longer ZiS-4 main gun and the ZiS-4 would also be fitted to T-34bb/57s (see below).

[3] The Red Army was anxious for diesel power for fuel commonality with their domestically-produced T-34/76 fleet. (The full Soviet designation was T-34bb(dd) for Britanskiy-Birmingemskiy dizel'nyy dvigatel' but, in Red Army usage, this was invariable truncated to T-34bd.) The Raptor was a development of the Rail incorporating diesel elements from the Nuffield-built Roadrunner 6-cylinder engine.

[4] Mk.II was a British admin designation for the T-34bb/57 - a Mk.I delivered with its turret adapted to take high-velocity Soviet guns upon arrival (these being 57 mm ZiS-4 L/73 cannons).

[5] Lucky shots from a Churchill's 6-pounder were able to disable a Tiger at Robaa, Tunisia, in February 1943. The similarly-armed Cossack Mk.IA was not ideal but its well-sloped hull was, at least, better-protected than that of Churchill.

[6] The A34 Cossack Mk.V series turret ring size was the same as that of the original T-34/76. Since the earlier A34s had removable spacer rings, in theory, any early-model A-34 could be upgraded with the larger turret.
« Last Edit: September 05, 2021, 06:59:44 AM by apophenia »
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