Western Allied Mechanical

On the Genesis Marina job, which is a multi-floor lab buildout in Brisbane, California, the WAM Prefabrication team, spearheaded by the department superintendents Randy Freitas and Cyrus Patel, worked closely with both the shop foremen and field foremen to develop a plan for what could and couldn’t be prefabricated on the job. There were two main constraints for the project that drove prefabrication efforts, the first of which being the delivery windows, as WAM crane accessibility was 2-times per week between 4:00am – 6:00am. This required significant pre-planning and preparation from the shop teams, as larger sections of prefabrication duct mains and control valve assemblies were separated and loaded by floor. Each needed to be completed in the shop and loaded by the end of working day prior to the day of the lifts, so that on-site lifting activities could proceed immediately starting at 4:00am.

The second constraint limiting what was able to be prefabricated was the elevator size, which is a common restriction in the Construction industry as a whole and creates unique challenges for how trades can load, store, and move material around a jobsite efficiently. Additionally, WAM evaluated using prefabricated Variable Air Volume (VAV) box sections – which would include the VAV itself, as well as the sheet metal plenum and piping trim. However, we realized that at the frequency in which VAV’s would need to be available to on-site crews, that flying these with limited crane availability was not feasible. This constraint for how large of a prefabricated section could be loaded on the elevator, led to the idea of using carts for the Genesis Marina job designed for loading VAVs and plenums.

The carts were specifically detailed with the dimensions of the elevator in mind, which allowed field crews to roll 4 VAVs at a time with plenums into the elevator and onto a floor, for simplified on-site moving and hanging of the boxes. As an added benefit, it also helped to save the limited available crane time for the two days permitted, otherwise large pallets of VAVs would have needed to be loaded directly onto the floor. As it relates to the VAV piping for Genesis Marina, full trim kits were not pre-piped on the VAV boxes, but instead just the brazed male adapter connection to the coils was prefabricated in the shop. For certain projects in the future, WAM is looking to include full trim kits pre-piped for transportation to the field.

Ultimately, when working with the prefabrication team at Western Allied Mechanical, the “Driven By Innovation” core value could include “and Revised by Iteration” as feedback received from shop and field crews throughout and following a project shapes the process. In other organizations, feedback about the constraints and obstacles can often be seen as a reason to slow down efforts – however, the WAM Prefabrication team sees all the feedback as opportunity. As Winston Churchill famously said in 1925, “To improve is to change; to be perfect is to change often.”