Posts Tagged: 1993

Report from terrain trials with T-80U

In late 1993, following the de-escalation after the end of the Cold War, the Swedish army borrowed two Russian T-80U’s and subjected them to a number of trials. Unfortunately, they arrived too late to compete directly with the M1A1, Leclerc and Leopard 2, which had been tested earlier as a part of the procurement of a new MBT for the Swedish army. In the end, the Leopard 2A5 with some Swedish modifications was chosen and entered service as the Strv 122 – you can read more about the procurement process and trials on Rickard O. Lindström’s excellent page. Most of the test results are still classified, but a friend got a report and some video tapes from the T-80U terrain trials declassified recently. The report originally contained comparison values with the Leopard 2 and the M1A1, but unfortunately those were blacked out by the national archives before they agreed to release the report to the public. Russian secrets are not as secret in this country as American and German secrets are.

The videos from these trials are available on YouTube (note that this report only covers the autumn trials, not the winter ones):
Part 1 (autumn 1993)
Part 2 (winter 1994)

Read the entire report as PDF (34 MB)

Some translated quotes from the report:

Summary

With 26 hp/tonne, the T-80U drives and accelerates very well in general. The difference in engine power between the T-80U and strv 104 (re-engined Centurion, nominal top speed 50km/h) is very noticeable on surfaces with some resistance, such as grassland or plowed fields. The T-80U is generally twice as fast as the strv 104 on these surfaces.

The suspension is good and allows high speeds over terrain without much discomfort for the crew.

Despite the antiquated steering system, with a good driver the tank does well in rough terrain, mostly thanks to its high engine power and good visibility for the driver.

Driving in rough terrain or narrow passages in the dark is considerably more difficult, mostly because the driver’s night vision periscope has a very limited field of view.

The tank has a very low reverse speed, which – among other things – limits its tactical options in prepared fighting positions.

The T-80U also does well with various obstacles such as steep slopes, trenches and road banks. The performance is however limited by the lack of self-cleaning tracks, which makes it tend to lose traction.

Re-positioning between prepared positions

If the re-positioning only involves driving forwards, the T-80U performs on par with modern western tanks. If reversing is involved, the T-80U is slower because of its low reverse speed.

In daylight, both the tank commander and the driver have good visibility forwards. When reversing, the commander has some problems with his visibility backwards since equipment on the turret are in the way.

When reversing in darkness, the tank commander has to turn the turret to the 6 o’clock position in order to get night vision so he can direct the driver.

Driving in difficult terrain

In daylight
T-80U average speed: 19.3 km/h
T-80U fuel consumption 201 liters/10 km
Strv 104 average speed: 14.4 km/h

In darkness
The same track as in the daylight trial was attempted, using the driver’s combined vision port (active IR and image intensifier). The trial was aborted after the tank had driven 300 meters in 60 minutes. Leopard 2 and M1A1 both have night vision devices well suited to this kind of driving.

Summary
When driving in daylight, the T-80U could maintain a relatively high speed. The driver’s visibility, the engine power and the steering system are all good enough for this kind of driving.

Driving in darkness, however, is very problematic. The driver’s field of view is so narrow he cannot see the tank’s corners. Since the turret has to be put in the 6 o’clock position to avoid damage to the gun, the tank commander cannot help him either.

Fuel consumption when driving in this type of terrain is very high.

Vertical obstacles

With the splash guard fasteners removed (20 minutes of work), the tank climbs a 1 meter tall vertical obstacle without any trouble. Without removing them, the tallest climbable obstacle is 0.8 meters.

Steep slopes

The tank does well up to a slope of about 25 degrees. The engine power is sufficient and if the surface is dry the track traction is good.

Top speed

On pavement, forward: 70.3 km/h
On pavement, backward: 11.3 km/h
On a grass field: 49.8 km/h
On a plowed field: 37.7 km/h

Slalom driving

Since every gear on the T-80U has a fixed turn radius, the tank has to be driven on the lowest gear to be able to make the tight turns, and it gets a result on par with the strv 104 despite being capable of much higher speeds.

The driver has some difficulties seeing when he’s past an obstacle; the commander has to direct him.

Time to prepare for fording

Depths up to 1.8 meters: 5 minutes
Depths exceeding 1.8 meters: 30 minutes

It is quick and easy to prepare for shallow fordings (up to 1.8 m).