As we probably all know, Vice City for the PC was ported via a potato which left us with many broken and missing features, including this one. The original PS2 game HAD models for the crane top, but this was left out for the PC port (R* vision)

Quick demonstration video showing the restored crane in action



UPDATED 14-11/15

Instructions

Add cranetopa.dff to GTA3.IMG
Open generic.col using Steve M's Collision File Editior and add cranetopa.col

open data\maps\generic.ide and scroll down to 638, ap_jumbo_01, ap_jumbos and add this line below
5040, cranetopa, cranes, 1, 750, 0

open data\maps\docks.ide and find
842, LODnetopa0, lod_docks

rename to LODnetopa0, cranes

after 860, dockgrass, dockgrass add this line below
5040, cranetopa, cranes, 1, 750, 0

add this to docks.IPL
5040, cranetopa, 0, -877.838, -1478.92, 113.205, 1, 1, 0, 0.5, 0.866025 1 1 1 0 0