How It's Made

Season 23 Episode 4: Railway Bridge Ties, Membrane Filters, Hydraulic Post Drivers, Bi-Planes

Heavy timbers are cut, drilled and treated for use as railway ties on bridges. Selective membranes are formed and installed in filtration units; hydraulic mechanisms are assembled into machines that drive posts into the ground; and wooden or metal airframes, wings, control surfaces and engines are brought together to build biplanes.

Genre:

Documentary

Seasons:

32

Episodes:

416

Cast:

Lynne Adams

Quality:

HD

Duration:

21 min

First Air:

2001

Rating:

7.7