History Podcasts

Cruiser Tank, Sentinel AC IV (Australia)

Cruiser Tank, Sentinel AC IV (Australia)

Cruiser Tank, Sentinel AC IV (Australia)

The Sentinel AC IV was a version of the Australian Sentinel AC I cruiser tank, modified to carry a 17pdr high velocity anti tank gun.

The original AC I was armed with a 2-pounder anti-tank gun, already obsolete by the time the tank entered production in the summer of 1942. The AC III was developed to solve this problem, and carried a 25pdr howitzer. This required the production of a new larger cast turret, and an increase in the size of the turret ring from 54in to 64in. Other changes included the use of a common crankshaft, which saved space and allowed the installation of more fuel, and the removal of the bow machine gun and associated crew member.

The prototype AC III underwent trials in February 1943, and was accepted for production, although Sentinel production ended before this happened.

Although the 25pdr armed AC III would have been a good close support tank, it would have lacked anti-tank capabilities. Work thus began on fitting the high velocity 17pdr anti-tank gun in the Sentinel.

In March 1943 the AC III prototype was armed with two 25pdrs in a co-axial mount, in order to test the impact of the high recoil forces generated by the 17pdr. The Sentinel passed these tests, and later in 1943 the 17pdr was installed in a prototype, with the designation AC IV. The AC IV underwent tests late in 1943, but by then the Sentinel programme had already been cancelled, and excellent AC IV didn't enter production.


A constant improvement

This, however, was not the finalized design and work would be ongoing for the AC IV until the cancellation of the tank program in mid-1943. Concerns had been raised about the design which would further complicate the matter. The 54 inch turret ring had been considered cramped but workable with the 25 pounder, but there were doubts about the efficiency of loading a 17 pounder in a 64 inch turret ring. It was therefore decided to increase the turret ring diameter to 72 inches for production vehicles.

Additionally, the Army was not satisfied with the proposed quantity of 54 rounds of ammunition carried in the prototype, and insisted that a minimum of 74 rounds be met. It was also considered desirable to mount the 25 pounder in the new turret to take advantage of the potential benefits of the 25 pounder gun alongside the 17 pounder.

The DAFVP responded to these requests with a proposal for an AC IVA design. Documents, however, are unclear as to what the AC IVA design actually entailed. Some documents claim the AC IVA was to be a variation of the AC IV fitted with the 25 pounder and produced at a rate of one 25 pounder armed tank for every three 17 pounder armed tanks. Other sources list the AC IVA as a design with enlarged hull dimensions to allow for an increased turret diameter and increased ammunition stowage for either the 17 or 25 pounder gun.


Sommaire

Le Sentinel fut conçu en novembre 1940 comme un char Cruiser équipé du canon britannique Ordnance QF 2 pounder (d'où son nom d‘Australian Cruiser tank Mark 1 ou AC1). Comme le char Ram canadien, il était basé sur le moteur, le roulement et la caisse du char américain M3 Lee, avec une tourelle ressemblant étroitement à celle du char britannique Crusader. L'utilisation d'éléments existants, simplifiés quand c'était nécessaire, mettait sa fabrication à la portée des capacités industrielles de l'Australie.

En 1942, pour essayer de rester au niveau des progrès des chars allemands, ses caractéristiques commencèrent à se rapprocher de celles d'un char moyen américain.

En février 1942 , l'AC1 fut baptisé "Sentinel". Sa fabrication fut assurée par la New South Wales Railways à la Chullora Tank Assembly Shops à Sydney. Les premiers exemplaires sortirent en août 1942 et firent leurs essais sur place. La tourelle et surtout la caisse étaient fondues d'un seul tenant cette technique n'avait encore jamais été utilisée pour une caisse de char à l'époque [ 2 ] .

Le Sentinel avait été conçu pour le canon Ordnance QF 2 pounder (40 mm), puis ses spécifications avaient été changées pour recevoir le canon Ordnance QF 6 pounder (57 mm). Cependant, au moment de sa production, celui-ci n'était pas disponible, et il fallut se rabattre sur le canon de 2 livres. Il y avait aussi une mitrailleuse lourde Vickers coaxiale en tourelle, et une autre à l'avant de la caisse. Les moteurs aptes à propulser un char de 28 tonnes, le Pratt & Whitney Wasp en étoile (à essence) ou le Guiberson en étoile (diesel), n'étaient pas non plus disponibles en Australie : le Sentinel reçut trois moteurs Cadillac V8 de 5,7 L (à essence) montés en trèfle.

En juin 1943, 65 exemplaires avaient été produits [ 3 ] .

Au Sentinel aurait dû succéder l'AC3, un modèle grandement amélioré par un meilleur blindage et une puissance de feu accrue. Un canon de forte puissance était disponible en Australie : l'obusier QF 25 livres (87,6 mm), qui fut rapidement transformé en canon de tank grâce à l'expérience acquise sur le canon Short Mark 1 de 25 livres (une version australienne raccourcie du QF 25 livres sortie en 1943). Monté sur une nouvelle tourelle, plus grande que celle du Sentinel mais utilisant le même anneau de tourelle de 1,37 m de diamètre, il laissait peu de place à son personnel mais donnait à l'AC3 des capacités anti-char, ainsi que la possibilité de tirer des obus à haut pouvoir explosif. La mitrailleuse de caisse et son servant étaient supprimés pour faire de la place pour ses munitions. Les moteurs Cadillac étaient maintenant montés sur un embrayage commun pour former le moteur Perrier-Cadillac 24 cylindres de 17 L, assez semblable à l'A57 Chrysler multibank qui propulsait certains chars américains M3 Lee et Sherman M4. Un prototype de l'AC3 avait été fabriqué et la production de 25 exemplaires pour des essais avait commencé quand le programme fut arrêté ( juillet 1943 ).

On construisit aussi une tourelle expérimentale pour tester la capacité du Sentinel à recevoir le meilleur canon anti-char allié, l'Ordnance QF 17 pounder britannique (76,2 mm). On y installa deux obusiers QF 25 livres : mis à feu en même temps, leur recul excédait largement celui du QF 17 pdr [ 4 ] . On y installa ensuite un QF 17 livres, et après des essais réussis, ce canon fut choisi pour le futur AC4 [ 5 ] .

Histoire au combat Modifier

Aucun Sentinel ne servit sur le champ de bataille. Après leurs essais et la fin du programme, ils furent tous stockés jusqu'à la fin de la guerre.

Tous les exemplaires furent démontés ou détruits en 1945, sauf trois [ 8 ] .

Ceux qui restent sont visibles au Musée du Royal Australian Armoured Corps de Puckapunyal (État de Victoria) (n° de série 8030), et en Angleterre au Musée des blindés de Bovington, dans le Dorset (n° de série 8049). Le seul AC3 produit (n° de série 8066) se trouve au Treloar Technology Centre à l'Australian War Memorial de Canberra.


Perrier-Cadillac 41-75 Tank Engine

As World War II started to gain momentum and become a global conflict, Australia realized that it was in a precarious position. In the war’s early years, Australia did not have an industry devoted to building war material, and the ability of other nations to supply war machines to Australia was in doubt. Australia realized that they would need to develop their own war equipment. In November 1940, Australia began developing its own tank, the Australian Cruiser Tank Mark I (AC1).

The “clover leaf” Cadillac drive system of the Australian Cruiser Tank Mark I. The rear engine (top of image) is not visible, but its long drive shaft can be seen passing between the other two engines. All three drive shafts connect to the transfer box (bottom of image).

The AC1 Sentinel was based on the United States M3 medium tank, but selecting a power plant for the AC1 proved to be a challenge. The M3 was powered by a 400 hp (298 kW) Wright R-975 radial engine, built under license by Continental Motors. But a continuous supply of R-975 engines, Guiberson diesel engines, or any powerful engines could not be assured to Australia. A solution was found in the unlikely form of a Cadillac V-8 engine originally used to power various coupes and sedans. The Australians referred to the engine as the Cadillac 75 because of its use in the Cadillac Series 75 sedan, but it was also used in the Series 70 and various Series 60 automobiles.

The Cadillac 75 engine had made its debut in 1936. It was a flat head (side valve) engine with the intake and exhaust valves located on the Vee side of the cylinder. The engine was a monobloc design with cylinder banks cast integral with the crankcase. The V-8 also incorporated hydraulic valve lifters for durability. The engine was designed to be built more economically than Cadillac’s V-12 and other V-8 engines. The Cadillac 75 engine had a 3.5 in (89 mm) bore, a 4.5 in (114 mm) stroke, and a displacement of 346 cu in (5.7 L). It produced 135 hp (101 kW) and weighed around 890 lb (404 kg).

The Australian Cruiser Tank Mark III (AC3) powered by the Perrier-Cadillac 41-75 engine. Only one AC3 was fully assembled, and that tank is currently preserved at the Australian War Memorial in Campbell, Australia. (Australian War Memorial image)

The Cadillac 75 engine was readily available for import to Australia, but its 135 hp (101 kW) output was insufficient to power the 28 ton (25.4 metric ton) AC1 tank. As a result, AC1 designers, Colonel W. D. Watson and A. R. Code, decided to use three engines to power the tank. Watson was a British tank engineer on loan to Australia, and Code was the Director of Australia’s Armored Fighting Vehicle Production. The three-engine power package developed for the AC1 tank became known as a clover leaf arrangement and was built by General Motors’ Holden subsidiary in Melbourne.

In the clover leaf configuration, engine “3” was situated toward the rear of the tank, and engines “1” and “2” were located amidships, side-by-side. The engines were completely independent of one another, each having its own radiator and drive shaft. However, engine “3” also drove the cooling fan from six pulleys mounted on its driveshaft. The drive shafts for all three engines extended forward to a common transfer box near the middle of the tank. From the transfer box ran the final output shaft that connected to the tank’s gearbox. The AC1 tank could be run on two or even one of the Cadillac 75 engines.

Front view of the Perrier-Cadillac 41-75 engine illustrates the odd cylinder bank arrangement. Note the single output shaft and how each exhaust manifold collects exhaust from three cylinder banks. A water pump and generator are driven from a belt at the front of each engine section.

The clover leaf Cadillac power package produced 330 hp (246 kW) at 3,050 rpm and was somewhat successful, powering 65 AC1 tanks. However, the rear engine did experience occasional cooling issues as a result of unequal coolant flow. The clover leaf’s three drive shafts, remote transfer box, and separate cooling systems added weight and complexity. As the Australian Cruiser Tank Mark III (AC3) was being designed in 1941, engineer Robert Perrier sought to simplify the clover leaf Cadillac power package. Perrier, a Frenchman, had been sent to Japan by the French government in 1940 and had subsequently made his way to Australia as Japan entered the war.

The AC3 Thunderbolt was an improved AC1 with better armor protection and firepower. To increase the performance of the three Cadillac 75 engines, Perrier mounted them radially to a common crankcase made from steel plates welded together. One engine was mounted on top of the crankcase, and the other two were mounted about 60 degrees to the left and right of the top engine. This configuration resulted in a rather odd looking engine, with its lower cylinder banks some 210 degrees apart. The engine was known as the Perrier-Cadillac 41-75 it was a lighter, more compact power package than the clover leaf configuration.

Rear view of the triangular, welded-steel crankcase of the Perrier-Cadillac engine. The power from all three engine sections was combined at the rear of the engine, and a single output shaft passed though the large, circular openings in the crankcase.

The Perrier-Cadillac engine had a single cooling system with one radiator, but each engine section had its own water pump. The remaining engine accessories were separate and operated independently of one another. At the rear of the Perrier-Cadillac engine, the crankshaft of each engine section was coupled to a common combining gear. The individual engine sections could be decoupled from the combining gear. A drive shaft extended from the combining gear at the rear of the engine, through the crankcase, and out the front of the engine.

The single output shaft of the Perrier-Cadillac engine allowed the transfer box used in the AC1 tank to be omitted, saving space and weight. The single output shaft also decreased mechanical losses, enabling the Perrier-Cadillac to produce more power than the clover leaf package with its three-into-one transfer drive arrangement. The 24-cylinder Perrier-Cadillac 41-75 displaced 1,039 cu in (17.0 L) and produced 397 hp (296 kW). The engine weighed around 3,000 lb (1,360 kg).

Rear view of the 397 hp (296 kW) Perrier-Cadillac engine. Behind the cover at the center of the engine is where the individual engine sections are connected to the single output shaft.

While the Perrier-Cadillac engine worked well, it did not go into production. A number of AC3 tanks were being built, but only one of these was fully assembled. The further improved Australian Cruiser Tank Mark IV (AC4) design followed, and it also used the Perrier-Cadillac engine. By 1943, the supply of war equipment to Australia had not been greatly impacted by the war, and equipment was imported faster than it could be domestically built. Australian resources were better utilized on projects other than tanks, and the Australian Cruiser tank programs were cancelled. However, the imported tanks did not completely match the Australian Cruiser tank design requirements, nor did they eclipse the Australian Cruiser tanks’ performance.

As a side note, the Perrier-Cadillac 41-75 was not the only engine intended to power AC4. A new engine was under development it was comprised of four air-cooled, four-cylinder de Havilland Gypsy Major engines mounted in an H configuration on a common crankcase. Starting in 1941, Gypsy Major engines were produced under license at General Motors’ Holden plant. With its 4.65 in (118 mm) bore and 5.51 in (140 mm) stroke, the Quad-Gypsy engine would have displaced 1,495 cu in (24.5 L) and produced 510 hp (380 kW) at 2,500 rpm. The 16-cylinder engine weighed around 1,500 lb (680 kg). The Quad-Gypsy engine was domestically-built, simpler, more powerful, and much lighter than the Perrier-Cadillac engine.

The 16-cylinder, QuadGipsy engine would provide around 510 hp (380 kW) for the Australian Cruiser Tank Mark IV. Lighter and more powerful that the Perrier-Cadillac, the engine would have been built in Australia by General Motors-Holden. Concealed in the shroud around the output shaft was a fan to force air through the cylinders’ cooling fins. Various accessories were mounted on top the engine.

While similar engine concepts, no direct relation has been found between the Perrier-Cadillac and the Chrysler A57 Multibank.


U.S.S.R.

VI - Loza's Sherman

VI - T-34-85 Victory

VII - T-34-85 Rudy

VIII - T-44-100 [Hellfire]

VIII - T-54 first prototype(T-54 mod. 1) [Origin]

VIII - T-44-85 (In Testing)

X - T-22 Medium [Uncatchable]

Germany

VI - Pz.Kpfw. IV Schmalturm | Optional Star Wars Camo, in battle nickname (-o-) |

VII - Panther/M10

VIII - Panther mit 8,8 cm L/71

VIII - Panzer 58 [Mutz]

U.S.A.

V - Ram II (Technically Canadian)

VI - M4A3E2 Sherman Jumbo

VI - M4A3E8 Sherman [Shreaking]

VII - T23E3 [Nomad]

VIII - T25 Pilot 1 [Intrepid] (Tank in testing)

VIII - T26E4 SuperPershing [Predator]

VIII - T54E2[Shark]

United Kingdom

I - Medium Mk. I (No Longer in Tech Tree)

VI - AC IV Sentinel

VIII - Chimera[Phantom]

VIII - Defender Mk. 1

Japan

V - Type 3 Chi-Nu Kai [Shinobi]

China

VIII - Type 59 [Ding]

VIII - 59-Patton [Aratinga]

X - 121B[Invincible]

France

I - Renault R35 (Used to be II)

II - AMX 38 (Used to be III)

VIII - FCM 50 t [Titi] [Zizou] [Twister]

VIII - Lorraine 40 t

IX - AMX 30 1er prototype

The European Nation

VI - Strv 74 [SWEDISH] (Upcoming tank)

VII - Leo [SWEDISH] (Upcoming tank)

VIII - P.44 Pantera [Furious] [ITALIAN]

Hybrid Nation (World of Tanks Blitz Nation)

VI - Y5 Firefly

VII - T6 Dracula (Renamed to just "Dracula") [Two-Faced]


British Premium Sentinel Tank is missing its 1942 hull mounted penis

That's a different tank than the one we have in game. That is the Australian Cruiser (AC) I Sentinel, while what we have is the AC IV. well, sort of. A complete AC IV was never actually built from what I remember, just a turret, and they used a modified hull from an AC I during testing. The final design was going to use a hull closer to the AC III Thunderbolt, and the AC IV model that you occasionally see pictures of in a museum is the AC IV turret on the AC III hull.

AC I - Armed with a 2-pounder cannon, 65 built

AC III - Armed with a 25-pounder, 1 built

AC IV - Armed with a 17-pounder, design never finalized, 1 partly built.

What we have in game is based on the AC IV design.

EDIT: Slight correction, the one in the museum has a modified AC I hull (with the hull MG removed), the turret from the AC III, a replica of the AC IV mantlet, and a 17-pounder gun from a different tank.


Piper Cherokee Series Aircraft Information

Designed for personal use, flight training, as well as air taxi use, the Piper PA-28 Cherokee is a light aircraft which has the capacity for one crew member and three passengers. The empty weight is 1,201 lb (544 kg) and the loaded weight is 2,150 lb (975 kg). Cruise speed is 108 kn (124 mph, 200 km/h), stall speed is 47 kn (54 mph, 87 km/h), and the Piper Cherokee should never exceed 123 kn (142 mph, 230 km/h).

Aircraft in the Piper PA-28 Cherokee family are all-metal, unpressurized, single-engine, piston-powered planes with propellers, and stretching the fuselage to accommodate six people. The six seat variant of the Piper PA-28 is generally known as the PA-32. Various models of the Piper Cherokee include the Piper Cherokee 140 Cruiser, Piper Cherokee 140/160, Piper Cherokee 150, PA-28-151 Cherokee Warrior, PA-28-160 Cherokee, PA-28-161 Warrior II, PA-28-161 Warrior III, Piper Cherokee 180, Piper Archer Model, Piper Archer II, Piper Archer III, Piper Turbo Dakota, Piper Cherokee 235 Pathfinder, Piper Dakota, PA-28S-160 Cherokee, PA-28S-180 Cherokee, Piper Cherokee 6/260, Piper Cherokee 6/300, PA-28R-180 Arrow, PA-28R-200 Arrow, PA-28R-200 Arrow II, PA-28R-201 Arrow III, Piper Turbo Arrow III, Piper Arrow IV, and PA-28RT-201T Turbo Arrow IV. Unless otherwise mentioned, the model number of the Piper PA-28 always refers to horsepower. Models in the Piper PA-28 series compete with the Cessna 172, the Beechcraft Musketeer, and the Grumman American AA-5 series.

In the beginning, all Piper Cherokees had a constant-chord rectangular platform wing. This wing became popularly called the Hershey Bar wing because of its resemblance to the chocolate candy bar. In 1974, Piper switched to a tapered wing with a NACA 652-415 problem and a 2-foot-longer wingspan. Both wing variants of the Piper Cherokee have an angled wing root. The takeoff distance, cruise speed and landing distance is very similar between the Piper Cherokee models of the same horsepower with varying wing types. Some of the differences that exist in later taper-wing models can be attributed to better seals and fairings rather than the varying wing designs.

Piper used their traditional flight control configuration for the Piper Cherokee family. The horizontal tail is a stabilator with an anti-servo tab. The stabilator, stabilator trim, flaps and Stay Connected! Sign Up for News and Industry Updates. Sign Up


Cruiser Tank, Sentinel AC IV (Australia) - History

Finding a suitable engine for the tank caused some difficulty, compounded by the absence of a heavy automotive industry. Heavy Diesel engines were unavailable and such unusual alternatives as a Wasp single-row radial aircraft engine and a hybrid consisting of three banks of Cadillac cylinders mounted on a common crankcase in Y-formation (proposed by Professor A. F. Burstall) were considered. These, with their transmissions, were evaluated and the latter chosen.

First automotive trials of the AC-1 version, started in January 1942, were most successful, but gunnery trials were less so because the 2 pounder was obsolescent. As the need for tanks was urgent, however, production was instituted without proceeding through the pilot model stage and by June 1943 fifty-eight units had been produced and passed.

In the meantime an AC-3 version, mounting a 25 pounder gun, then the most powerful armament of any Allied tank, was under development, with a re-designed Cadillac engine system. A prototype appeared in February 1943 but did not go into production. By mid-year quantities of American General Grant tanks were arriving in Australia and all tank manufacture was cancelled. The AC-1 tanks that had been produced were used for training purposes by the Army under the name of Sentinel.


Australia
25pdr (short)

Czechoslovakia
Skoda 100mm 14/19 Howitzer

France
155mm Schneider, 75mm Schneider M 1904

Great Britain
25 pdr, 6 inch Howitzer (x2), 4.2″ Towed Mortar, 4.2″ Mortar, 5.5 inch Medium Gun, 3.7 inch Howitzer

Germany
210mm Morser 16, 152mm sFH13 Howitzer, 105mm FH16 Howitzer, 77mm FK16 Field Gun, LeFH18 Light Field Howitzer, 7.58 cm Minenwerfer, Granatwerfer 42 (mortar), and the extremely rare LeFH Kp16, 17.5cm Minenwerfer, 15cm sFH18 Heavy Field Howitzer, 8cm Granatwerfer 34 (mortar), 7.5cm LE IG 18 Light Infantry Gun

Japan
105mm Type 91 Howitzer, 75mm Type 31 Mountain gun, 70mm Type 92 Light Howitzer, 75mm Type 94 Mountain gun

Russia
76mm Model 1927, 152mm M1937 (ML20), 152mm M1938 (M10), 122mm M1930 (M30), 76mm Divisional Gun M1902, 85mm D44 Divisional Gun, 76mm Divisional Gun M1942 Zis-3

United States
155mm “Long Tom” M1, 155mm M114 Howitzer, 105mm M3 Light Howitzer, 105mm M2A2, MkVII 3″ Landing Gun, M1A1 155mm, 75mm Model 1917 Howitzer, M115 203mm Howitzer

Italy
OTO Melara Mod 56 (Ex Australian Army L5 Pack Howitzer)


Watch the video: The Char B1 that destroyed a Panzer Company (January 2022).