Professional Challenge...

The WSDOT declared special provisions in the project bid documents which

 "…require the drive to be the product of a single manufacturer. We do not

consider a value-added reseller to be a manufacturer. This is an unusual

application that, in our professional judgment, needs the expertise of the

engineers who design SCR (silicon controlled rectifier) drives. The project,

and the public who own the bridge, will not be well served by trying to use

a drive that has been cobbled together." The qualifications clause of this

project required that the systems vendor have a minimum of five years

documented experience in the design and manufacture of drive systems

for high inertia and overhauling loads. View of Seattle's Montlake Bridge

and the South Control Tower.