replicas of real trains. In addition, there are two small switcher locomotives that are used for non-passenger purposes. Most regular service, including all non-holiday weekday service, uses only two diesel trains. The steam train operates on only a few weekends per year and for special events. In the 1980s, two of the three trains were equipped with wheelchair lifts to allow mobility-impaired persons to board the train, and in 2005 these lifts were upgraded so as to better accommodate heavier electric wheelchairs. The Zooliner The Zooliner is a 5/8-scale replica of the diesel-powered Aerotrain, which is famous for its unusual shape that was influenced by automobile designs of the period when it was built, considered futuristic at the time. The Zooliner was built in 1958, its mechanical parts by Northwest Marine Iron Works and its streamlined bodywork by the H. Hirschberger Sheet Metal company of Portland. It first carried passengers in June 1958. The Zooliner is powered by a diesel engine with hydraulic transmission, which is WP&ZRy locomotive No. 2. The brakes are pneumatic, the same as on its full-size namesake. The train includes four or five streamlined passenger coaches pulled by matching locomotive No. 2. The rearmost car was rebuilt in late 2005 to resemble a dome car, in connection with installation of a larger and more powerful wheelchair lift. 4-4-0 No. 1, Oregon 4-4-0 No. 1 Oregon is a 5/8-scale replica of a classic American 4-4-0 steam locomotive of the 19th century. It was built in 1959 by the Oregon Locomotive Works. It is a scale copy of the 4-4-0 locomotive, Reno, of Nevada's Virginia & Truckee Railroad (built by Baldwin Locomotive in 1872). Unlike the original, No. 1 Oregon uses oil as a power source, but it is still a real steam locomotive (not a diesel that is made to look like a steam locomotive). It weighs about 8 tons. It first carried passengers on June 20, 1959, on the temporary Centennial Exposition line in North Portland, but was moved to the then-new Portland Zoo site around the end of the summer, when the exposition ended. The steam locomotive's original frame broke several times during its first two decades, but a new frame was built in 1982. The Oregon was taken out of service in August 2002, in need of extensive other repairs, and was almost retired and relegated to static display, due to lack of funds