Pat Dawson

Ouellette Bridge

A reversible clamp-and-leg system let one local steel fabricator illuminate the country’s longest lenticular truss bridge.

Preservation rules prohibited drilling or welding, so the fabrication package had to carry the entire installation logic without modifying a single original component.

FabricationPlaceExperience

Fabrication · Lowell · 2021

Role

Architectural designerFabrication-set author

Outcome

Five trusses and 100+ addressable lights installed with zero drilling or welding to original components.

The fabrication handoff

Reversibility was the design.

The 1880s bridge could be illuminated only if none of its original ironwork was drilled or welded. Reversible clamps and small legs supported custom housings along the road barriers, carrying warm light across five trusses without leaving a mark. Dimensions, tolerances, cable paths, and repeatable parts were resolved as one fabrication package so a single local steel fabricator could build and install more than one hundred addressable lights. The drawings had to make preservation executable in the field.

Fabrication details for housings that required no drilling or welding.
Fabrication details for housings that required no drilling or welding.
Installed housings carried light without altering the historic truss.
Installed housings carried light without altering the historic truss.

At a glance

5 historic trusses100+ addressable lightsZero modified original components

In the record

Clamp family and tolerance studiesFabrication sheetsInstalled night sequenceNon-invasive attachment mockupsCustom light-housing detailsCable-routing and installation sequence

Construction geometry translated a singular bridge into repeatable parts.
Construction geometry translated a singular bridge into repeatable parts.
Assembly studies resolved reversible attachments before fabrication.
Assembly studies resolved reversible attachments before fabrication.
01

Respect the artifact

The attachment logic preserved every original 1880s component and made reversibility a design requirement.

02

Draw the assembly

Custom housings, clamps, legs, and cable routes became repeatable local parts rather than bespoke field improvisations.

03

Hand it to one maker

The package was authored so a single local steel fabricator could understand, price, build, and install the full system.