Steam Generator Cars
With the F units aging and the steam generators becoming more
unreliable WP decided in 1968 to experiment with using freight units
to power the Zephyr. Borrowing a steam generator car from the D&RGW
a test run was made using U30B 754 on September 13, 1968. Another
run was made on September 15 also using the 754. Although the tests
were essentially successful two problems were identified on these
trips. After going through the car washer at Portola much time was
spent just keeping the unit running. It seems water from the
pressure nozzles got into everything shorting electrical circuits
and such. The second problem was a general shortage at the time of
Even though the decision to use freight power was abandoned the age and condition of the boilers in the F units was a concern. Having separate steam generator cars would take the strain off the F unit boilers while at the same time allow for the use of freight power if needed on an emergency basis. With this reasoning in mind WP purchased heater cars 1, 2 and 6 from the Great Northern in 1968 and renumbered them 591-593 respectively.
Cars 591-592 were built for the GN in 1928 and during refurbishment in 1946 received new Clarkson boilers. The 593 was built in 1913 and converted to a heater car by GN in 1943. It also had Clarkson boilers and in 1952 had a generator installed. Inside length of these cars was 39 feet 4 inches and they measured 43 feet 8 inches over the buffers. Each car is slightly different in appearance as to door, window, and ladder placement.