[1] The comparatively very small WES fleet includes three different types of diesel commuter rail cars.
TriMet had wanted to contract American firm Budd Corporation, but the company backed out at the last minute.
[10] TriMet announced it would purchase an additional seven vehicles in August 1983,[11] but a budget shortfall forced the agency to withdraw this proposal the following November.
[18][19] These cars were originally equipped with stop-request bell cords (as are commonly found on American transit buses), which passengers needed to pull to signal the operator that they wanted to get off at the next stop, similar to a typical bus or some streetcars.
Finally, in 1994, the bell cords were removed after TriMet adopted an operating practice of having MAX trains stop at every station at all times.
In 1995, TriMet began installing wheel skirts to cover these, to reduce noise, and said that these would be included on all LRVs purchased in the future.
[23] Starting in 2003, TriMet began a program to refurbish the bodies of the Type 1 cars, carried out by its own employees.
[25] The program proceeded at a slower pace than originally anticipated because of staffing issues,[26] with only two cars being worked on at a time, and each taking one to two years.
By 2018, when only 23 of the 26 cars had been completed, TriMet had terminated the program because, by that time, the Type 1 fleet was only a few years away from retirement.
[29] With the partial opening of Westside MAX in 1997, TriMet's "Type 2" light rail vehicles were introduced.
The Siemens model SD660 (originally SD600, but retroactively redesignated SD660 in 1998[30]) have a low-floor design, a first for light rail vehicles in North America,[31][32] digital reader boards and a slightly more open floor plan.
The floor is nearly level with the platforms, and small ramps called "bridge plates" extend (on request) from two of the four doors, enabling passengers in wheelchairs to roll on and off of the vehicle easily.
Siemens installed an improved air-conditioning system, more ergonomic seats and automatic passenger counters using photoelectric sensors above the doorways.
[36] Twenty-two new Siemens S70 low-floor cars, designated Type 4, were purchased in conjunction with the I-205 and Portland Mall MAX projects.
[5] TriMet placed the order for the Type 5 cars with Siemens in April 2012 and they began to be delivered in September 2014.
[46] Type 6 cars also feature a new paint scheme that TriMet introduced on its bus fleet in early 2019: overall blue with orange stripes.
[1] A Type 6 car was first shown to the public at a "Sneak Peek" event held on October 15, 2023, at the SE Park Ave MAX station.
[51] After a January 2004 Portland-area snow and ice storm that shut down the entire two-line MAX system for a day and a half,[52] TriMet decided to install second, ice-cutting pantographs on some Type 1 light rail vehicles,[24] which it would run (empty) all night under certain weather conditions, to prevent ice from building up on the overhead lines.
The 77 subsequent overhauls were originally planned to be carried out in the Portland metropolitan area, at former United Streetcar facilities owned by Oregon Iron Works, but those plans were later dropped, and all 79 overhauls are to be carried out at Siemens's own facilities in Sacramento.