In fact, it is a roughly th scale model of a dragline crane, plonked in the middle of his kitchen and stretching from floor to ceiling.
His work is a feat of model-building made more remarkable by the fact Mr Colley is almost blind, and works largely by feel.
He told the Otago Daily Times he began building the crane this year, when his deteriorating sight made smaller models ''too awkward'' to work on.
''This is something I can do.''
He has spent a lifetime working on mechanical gadgets, vintage machinery, models and motors, and was a founding member of the Otago Vintage Machinery Club and editor of its newsletter.
His previous projects included a model tractor and a long list of mechanical gadgets, but nothing
quite so big, he said.
''This is by far the biggest thing I have ever made.''
The project began about eight months ago on his kitchen table, but as the size of the crane expanded, so did his work area.
''It started on the kitchen table and finished up on the kitchen floor,'' he said.
The ODT visited yesterday and found the crane dominating Mr Colley's small kitchen, stretching from one side of the room to the other and from floor to ceiling.
Perhaps luckily for the project, Mr Colley said he did not have a wife and was at home every day, meaning the crane's construction had become ''a full-time job''. Mr Colley said he was partially sighted, having lost all his sight in one eye and some in his other.
He had no design drawings or plans to help build the model crane, instead working by studying photographs and by feel, and relied on donated aluminium after a few false starts using steel.
He planned to display the results of his labour at next month's Otago Taieri A&P show.
''To me, this is an achievement because everything was actually done by feel and what remaining sight I have, and damn good guesswork.''