Spike LR ATGM of Azerbaijan Army in action

 

Soviet T-72M tank in China

In the 1980s, China acquired a Soviet T-72M tank via Romania and reverse engineered it. China kept to  it secret. The analysis and testing of this tank was officially released now.

 

Very rare T-80UD with Kontakt-1 ERA.

The T-80UD main battle tank was developed by the KMDB at the beginning of the 1980s, adopted in 1985 and entered service with the Soviet Army in 1987.

Production of the T-80UD commenced in Ukraine in 1987. Around 700 of these MBTs were built. It was planned to become the main MBT of the Soviet Army, however with the collapse of the Soviet Union its production ceased in 1991. These tanks are currently in service with Russiaб Ukraine and Pakistan (Pakistan Army bought 320 T-80UD tanks in 1996).

The T-80UD is powered by the 1,000-hp 6TD-6-cylinder opposed-piston  multi-fuel two-stroke turbo-piston diesel engine, ensuring high fuel efficiency and a long cruising range. The T-80UD shares most of the T-80U's improvements, but can be distinguished from it by a different engine deck and distinctive smoke-mortar array and turret stowage boxes. It retains the remotely-controlled commander's machine gun.

Early version of T-80UD was equiped with Kontakt-1 ERA, then it changed to the Kontakt-5 ERA. The follow pictures showing one of this rare vehicle with K-1 ERA.

Via panzer35.ru forum.

Gross and Net HP of Tank engines

Horsepower is officially defined as "the amount of energy required to lift 550 pounds, one foot, in one second." This definition dates back to when cars didn't even exist and, despite the worldwide acceptance of the metric system (America not withstanding) in which feet have been replaced by meters, the definition remains in use today.

Generally speaking, horsepower is an indication of how capable a vehicle is at moving itself around and, consequently, the more horsepower a vehicle possesses, the quicker it can move between two points. In addition to determining how quickly a car or truck can move, horsepower has a direct relationship to top speed. As a vehicle's speed rises, additional horsepower must be expended to push it.

So if the definition of horsepower is so straightforward (550 pounds moved one foot in one second), how can the same vehicle have different horsepower ratings? For instance, Leopard-2 MBT have the 47.6-liter  MB-873 Ka-501 engine at 1500 horsepower. Yet  in realiti the tank  has 1252 horsepower. So what gives?

Gross output, is the output of a ‘bare’ engine running on a test stand with no external engine-driven accessories (e.g., alternators or water pumps), free-flowing exhaust headers with no mufflers, and optimal ignition timing. Gross ratings are also mathematically corrected for standard atmospheric conditions. In other words, gross output represents a particular engine’s maximum output under ideal conditions.

Net hp is what the engine is capable of in a car. It is also taken on an engine dyno at the flywheel, but with the engine equiped as it would be in the car. Stock air filter assembly, cooling system, stock exhaust mainfolds running through stock mufflers, various engine-driven accessories, including the engine’s own water pump and generator/alternator and add-ons like the power steering pump and air conditioning compressor. Engines intended for on-road use typically also have restrictive air cleaners and exhaust systems, sound-deadening mufflers, and emissions-control add-ons like catalytic converters and thermal reactors. Engine tuning is further compromised in the interests of reduced noise, better drivability, improved cold-weather performance, and lower exhaust emissions. All of these factors reduce the engine’s maximum output in ways that the gross rating methodology does not reflect. 

Below we can see Gross and net HP of different tank engines

M4 Sherman with composite plastic armor

 HCR2 for M4 Sherman tanks, one of the first composite armors.

The devastating effect of the lightweight German hollow charge weapons such as the Panzerfausts and Panzerschrecks (encountered by US forces in the European theater) re-sulted in all sorts of field improvisations to strengthen the Shcrman's armor. At the same time. Ordnance initiated several programs to develop protection a-gainst these weapons.Much of the test work extended into the postwar period.

One such project evaluated the use of plastic armor added to the sides of the hull and turret. One of the experiments showed that plastic armor was able to achieve the same level of protection as steel but with a much lighter weight.

The armor was further improved through a series of tests and resulted in two variants, the HCR1 and HCR2.

HCR1 was composed of:

• 50% aluminium fillings

• 40% asphalt or pitch

• 10% wood flour

HCR2 was composed of:

• 80% gravel

• 5% wood flour

• 15% asphalt or pitch

HCR2 proved to have the best performance and the original plan for tank protection with plastic armour was to produce HCR2-filled steel panels that could be readily fitted to Allied tanks. However, this project was abandoned due to the low probability of these weapons becoming a serious threat.

The HCR2, was a mixture of quartz gravel and a mastic composed of asphalt and wood flour. A kit of auxiliary plastic armor was designed by the Flintkote Company for the M4 series of tanks. The armor panels consisted of 10 inches of HCR2 faced with 1 inch  aluminum plate. These panels were held in place over the sponsons and around the turret by 1/2 inch steel cables attached to brackets welded to the tank. The plastic armor kit increased the weight of the vehicle by about 8 tons. Tests at Aberdeen in the Fall of 1945 showed that the turret assembly could defeat the German Panzerfaust 100 or the 8.8cm rocket, but both weapons caused some penetrations on the sponsons. The plastic armor also increased the protection against the kinetic energy projectiles such as the 76mm H VAP, but not as much as an equivalent weight of steel. It was also noted that the attachment cables were vulnerable to attack by high explosive rounds sometimes resulting in the complete loss of an armor panel.

First serial Su-57 on the way to the service place

The first serial Su-57 (the russian 5th generation fighter jet) left the KnAAZ and headed to the base