
Boiler Wall Tubes Circa 1970s
Section of boiler wall from Clover Bar
This is a section of furnace wall tubes; this type is known as a membrane wall as the furnace is pressurized.
Below is a section of Clover Bar No. 4 boiler wall being cut out during demolition (January 19, 2007):

Manufacturer Babcock and Wilcox
Specifications: Radiant Boiler
Heating Surface: 79,778 sq.ft.
Pressure 2100 psi