The site comprises four sections, six open engine testing stands constructed in 1942, two enclosed testing stands constructed in 1943, two open stands constructed in 1943 and the concrete flooring and footings of a hut and warehouse.
The chief characteristic of the site is the functional nature of the design of each section.

The most prominent features of the six open engine testing stands constructed in 1942 are the six reinforced concrete walls which separated the testing stands and provided a degree of protection against excessive noise or a propeller malfunction.
Stands 1 to 4, numbered from the north, have been constructed on a raised concrete platform 40 centimetres (16 in) above ground level.
Parts of its flooring have been raised higher above the general level of the platform.
They indicate the positions where each engine stand and its respective control cabin would have stood.

Most of the remaining evidence of the purpose and working life of the site is on the platform.
Of the monorail above each engine, only the vertical I-beams, cut off at their base, indicate where they were situated.
Engines and propellers were manoeuvred into position using a block and tackle which ran along this monorail.
Four steel circles set in the concrete, the legs of the barrel-type engine stands cut off at their base, show the engine stand position.
What remains of the timber sleeper and bitumen floor along the frontal width of stands 1 to 4 delineates the position of the propeller arc.
Drum caps, steel plates and pieces of cloth are embedded in the bitumen.

The two enclosed stands from 1943 have been constructed using brick walls set on a concrete foundation.
The pattern of the 35-centimetre (14 in) thick walls is a variation of English bond.
The roof of each is reinforced concrete and features eight vertical fins.
The southern enclosed stand is open at both its eastern and western ends and has a concrete floor.
Two doors and two windows open towards the central area in which a brick control cabin with a reinforced concrete roof is located.

The design and construction of the northern enclosed stand mirrors that of the southern one.
The horizontal I-beam section of a monorail, rated for a maximum loading of 2 long tons (2.0 t), is positioned close to the ceiling at the eastern end of this stand.

Of the two walls built to protect workers in the two open testing stands constructed in 1943, only one remains standing.
The control cabin that served both stands is built of concrete, while two distinct, raised platforms on each side of the control cabin, both with the circular footprints of the barrel-type stands, attest to the position of the test engines.
Oil residue indicates the position of the propeller arc.

To the north-west of the enclosed test stands are the concrete footings of a hut constructed in 1942.
Immediately north of this are the footings and concrete floor of a warehouse constructed in 1943.
Both are surrounded by concrete pavement.

Most sections of the stands site have altered little since the fixtures used for engine testing were removed, however modern concrete block walls constructed to ceiling height in the northern enclosed testing stand have created a secure room occupying approximately one third of the structure.
The site comprises four sections, six open engine testing stands constructed in 1942, two enclosed testing stands constructed in 1943, two open stands constructed in 1943 and the concrete flooring and footings of a hut and warehouse. The chief characteristic of the site is the functional nature of the design of each section.
The most prominent features of the six open engine testing stands constructed in 1942 are the six reinforced concrete walls which separated the testing stands and provided a degree of protection against excessive noise or a propeller malfunction. Stands 1 to 4, numbered from the north, have been constructed on a raised concrete platform 40 centimetres (16 in) above ground level. Parts of its flooring have been raised higher above the general level of the platform. They indicate the positions where each engine stand and its respective control cabin would have stood.
Most of the remaining evidence of the purpose and working life of the site is on the platform. Of the monorail above each engine, only the vertical I-beams, cut off at their base, indicate where they were situated. Engines and propellers were manoeuvred into position using a block and tackle which ran along this monorail. Four steel circles set in the concrete, the legs of the barrel-type engine stands cut off at their base, show the engine stand position. What remains of the timber sleeper and bitumen floor along the frontal width of stands 1 to 4 delineates the position of the propeller arc. Drum caps, steel plates and pieces of cloth are embedded in the bitumen.
The two enclosed stands from 1943 have been constructed using brick walls set on a concrete foundation. The pattern of the 35-centimetre (14 in) thick walls is a variation of English bond. The roof of each is reinforced concrete and features eight vertical fins. The southern enclosed stand is open at both its eastern and western ends and has a concrete floor. Two doors and two windows open towards the central area in which a brick control cabin with a reinforced concrete roof is located.
The design and construction of the northern enclosed stand mirrors that of the southern one. The horizontal I-beam section of a monorail, rated for a maximum loading of 2 long tons (2.0 t), is positioned close to the ceiling at the eastern end of this stand.
Of the two walls built to protect workers in the two open testing stands constructed in 1943, only one remains standing. The control cabin that served both stands is built of concrete, while two distinct, raised platforms on each side of the control cabin, both with the circular footprints of the barrel-type stands, attest to the position of the test engines. Oil residue indicates the position of the propeller arc.
To the north-west of the enclosed test stands are the concrete footings of a hut constructed in 1942. Immediately north of this are the footings and concrete floor of a warehouse constructed in 1943. Both are surrounded by concrete pavement.
Most sections of the stands site have altered little since the fixtures used for engine testing were removed, however modern concrete block walls constructed to ceiling height in the northern enclosed testing stand have created a secure room occupying approximately one third of the structure.
Allison Engine Testing Stands