Having built many models of large size 7ft/2M long and weighing inthe region of 750lb/400Kg before starting work on them I made sure that the doorway to the workshop would permit the model to roll out on a steel track, with sufficeint space in the doorway to let me pass through wilst the modle was only partway through.
The golden rule with large models is NEVER plan on lifting them, always build a support frame, rails and wheels to move it on the track to a transport vehicle,
With a train it is built with wheels, but for a ship, build it on a wheels "trolley/frame" that can run on the track out the doorway and down to the trasnport vehicle.
SAFETY IS THE KEY. Let the track take the weight NOT YOU!
Keep the movement and STOPPING under control. NEVER stand in front of a moving/descending load!
PLAN AHEAD -BEFORE Building starts!