Here are the catenary references from the December 2020 Preliminary Design Business Case.
NOTE: It'll be an
overhead 1500 volt DC system, so the electrical transformers and rectifiers will presumably be in substations,
not on-board as noted in the articles posted by W.K. Lis above for ac systems, and the issues with added vehicle weight won't arise.
1500 volts DC is also a step up from the typical 750 volts DC.
The article posted by W.K. Lis also says that 1500 volts DC (vs 750 volts DC) allows wider spacing / fewer substations.
PS, the catenary masts do add height to the overall look of the guideway.
Here's Seattle's Link:
This 5 mile (8 km) stretch of light rail extends from Boeing Field, at the southern outskirts of the city of Seattle, to the Seattle-Tacoma - SYSTRA IBT - Bridge Engineering
www.systraibt.com