(Marker position is approximate)
The crane was primarily to lift aircraft carrier borne aircraft fitted with floats up onto the airfield.
The aircraft in use at this time could be switched from operating on floats or wheeled undercarriages as deemed appropriate for their missions.
When not at Kai Tack the aircraft would be away on duties with the China Squadron’s aircraft carriers, HMS Argus, HMS Hermes & HMS Eagle which were rotated between their ‘China Squadron’ cruises.
Contemporary reports stated that if the steam-powered seawall crane was not operational as it required its steam boiler to be fired up, there was a practice of hooking an aircraft onto the crane hook and by the aircraft’s own engine power “flying off”, swinging the crane’s jib over the water. Then lowering the aircraft onto the sea.
This zoomed-in portion of a larger image shows that the steam-powered crane was fixed to the opposite side of the nullah to the aerodrome. On “private” land?
The earlier posted image of the unbridged nullah (see https://gwulo.com/media/44731) shows people sitting on what would have been the crane’s foundations.
Also shown is the taxiway to the crane for aircraft moving from the temporary mat-shed hangars.
The other access bridges across the nullah are clearly shown. The bridges across the nullah halfway up would have been to facilitate access for airmen living in the properties just across on the Kai Tack bund. No specific dates for the bridges construction I am aware of at present.
The heavy-weight bridge at the seawall could have been constructed to give access via Kai Tack bund and the now developed roads in Kowloon, rather than the other access to the site at the northwest corner of the airfield.
With no obvious fencing or security gates in view the aerodrome site must have been wide-open to anyone.
This image from 1937 shows that the nullah is no longer bridged and the crane has disappeared
Re: Steam Crane
Mention is made in the The Fleet Air Arm of the crane's operation in lowering seaplanes into Kowloon Bay.
Re: Slipway, Steam Crane and Nullah Bridges
The 1937 photo of the Kai Tak seawall shows the marine terminal and pontoon. Not in the photo but immediately to the left or east of the marine terminal would be the civilian slipway (completed in 1934) for seaplanes. The RAF on the eastern side of the airfield had their own slipway.
The steam crane probably became redundant and disappeared when the Civil Airport opened in February 1936.
Although the Aerodrome was completely fenced-in by 1934, I am not sure when the nullah bridges were removed.
Sources: Reports of the Harbourmaster 1934-1936.