Steam Happens #24: Building a New Roberts-Type Boiler


Our boat, A Boy's Will,  with my 50 year old Olfeldt boiler


Olfeldt boiler in boat

Olfeldt boiler diagram showing position above firebox. Note lack of  "waterlegs"
surrounding firebox.

New Roberts-type boiler core drawing


End pieces removed to show water tube pattern

Steel core components welded

Bending table with mosaic of tubes full-scale and bending tools

Close-up of alternating tubes with  2 inch nipples on outer row

Steam drum tube ends

Tubes installed but not given final alignment adjustment. Forgot to take photos after final adjust...Oops!

Base fabricated. Note hangers for rebar fire grate

Core on base showing ashpit door

Note that base corners are open in above photo.
Smokebox slides between corners and sides of base,
and is also secured by two bolts above ash pit door as well as two bolts in rear.
This makes it very easy to remove entire external box assembly. from base and core.


Smoke box with aligned hole patches. Note rear end piece with insulation
already mounted and front end piece on table, insulated with standoffs in place
ready to mount in front. See below for details of standoff spools.

Nuts temporarily mounted
on spools.

Wooden boiler cladding. Note fasteners.

Click on above photo to view YouTube video and more detail of boiler

Various fasteners used in boiler