Conservation - "G for George"
Lancaster Conservation Progress Report - March, April & May
A diverse range of conservation work has been done on the Lancaster during the last 2 months.
The structural elements of the undercarriage have been dismantled, cleaned and repainted.
Undercarriage Oleopneumatic struts before treatment
Undercarriage Oleopneumatic struts after cleaning, treatment and repainting
Work is presently continuing on the wheels. The surface of the tyres is being treated to repair handling damage, and incorrectly applied paint is being removed from the brake hubs and wheels. These will soon be repainted in the correct colours.
All four of the Rolls-Royce Merlins have had their internal coolant passages flushed. Two of the Merlins have now been chemically treated, rinsed and dehumidified1. Soon, a vapourising corrosion inhibitor2 will be added to the water tanks and the radiator/water system will be sealed. Although the engines are largely complete, the work of locating small missing items like sparkplugs and wiring fittings continues.
Rolls-Royce Merlin engine having its coolant system flushed of deposits
Rolls-Royce Merlin engine being dehumidified after flushing to prevent corrosion
The port wing and centre-rear fuselage are currently undergoing treatment.
The inboard wing roots4, taboo ring5
and tail-gunner's ammunition tracks, which were damaged in the 50's,
have been repaired.
Historical photographs and manufacturers documentation are being used in conjunction with spot rubbing3 to locate the original camouflage and aircraft identification markings. This means that for the first time in 60 years, George can be accurately returned to the paint scheme and markings it had while in active military service.
Spot rubbings on the port wing to find the original camouflage
Chalkline marking out of the position of 1943 "ARG" markings on starboard side of fuselage
Large Technology Objects Conservator,
Australian War Memorial
Dehumidification means to remove all the moisture from a sealed airspace. In order for corrosion reactions to take place, water is needed. Dehumidifying stops this being able to happen.
An inhibitor is a chemical compound that prevents corrosion from occurring. A vapourising inhibitor can be enclosed in a sealed space and will flow through the system as a gas and coat the exposed surfaces of the metallic parts.
This is an investigative technique used to locate original markings which have been subsequently covered with newer layers of paint. Fine-grained abrasive paper is used to rub a small hole in the paintwork down to the original metal surface. Every layer of paint appears as a concentric ring of colour on the edge of the spot, with the oldest colours being nearest to the metal.
This is the most inboard section of a wing where it touches the aircraft fuselage. The joint between wing and fuselage is commonly covered with a cloth sealing strip or a metal fairing to smooth the airflow.
In the First World War, the guns mounted on aircraft were moved manually.
With the advent of hydraulically and electrically powered turrets in
the Second World War, it was discovered that a gunner could drive the
gun barrels into the side of the fuselage damaging either the aircraft
or the guns. The taboo ring fitted to the upper turret of the Lancaster
prevents this. As the guns are moved, the small wheels protruding from
the turret just below the guns operate a switch when they hit the curved
track on the taboo ring. This switch operates the hydraulic system and
elevates the guns, thereby ensuring a collision cannot occur.