Please note that you can see the former Pacific Electric Portable Substation 00186 in the background of the shot in Dominguez Junction
A portable sub-station is exactly as it sounds. Generally a piece of rolling stock with a sub-station on it. Jason
Just to expand for people not familiar with electric power, a portable sub station is designed to be "movable on rails" and capable to be hooked up to the main power grid. It has a transformer (and rectifiers if the trains run on DC) so that can provide either a power boost in case the traffic increases in a specific section (sub stations are spaced IAW train voltage and expected load, it can be anything between 10 to 40 miles) or to replace an inactive fixed sub station (for repairs or upgrade). In Italy on 3KV DC lines Sub Stations are spaced about 10 miles on mainlines, while on the high speed 25KV AC it is more than 20 miles (and with lots of more power). Here one of the italian mobile subs, notice the cables linking the equipment
I'm going to show that one to the boss. Our company makes test equipment for that kind of stuff. He's going to love this.
I don't recall the reason why, but I want to say it had something to do with the large size of the cars in comparison to the other PE equipment. Pacific Electric Coach 1001 at Travel Town in Los Angeles, mid-1950s (Herb Cearley) Pacific Electric "Hollywood" Car 5167 at Watts, CA, mid-1950s (Herb Cearley)
They guessed correctly, the Blimps were 67 feet over the bumpers and held 80 people while a Hollywood Car was 52 feet and held 65 people. Plus, they flew compared to the 45 mph Hollywood car
PE "Hollywood" Car 5166 at the head of a special at Bellflower, mid-1950s (Herb Cearley) PE "Hollywood" Car 5122 at Long Beach, mid-1950s (Herb Cearley)
This photo shows why the car behind and others were called "Blimps". They were much larger than the Hollywood cars.
Thanks bremner -- I've wondered about the blimp nomenclature for a while now. Thanks too Hytec -- that photo with the blimp behind the Hollywood car says it all. I'd have missed the true enormity of the blimps if you hadn't pointed it out.
PE "Hollywood" 5119 at Watts, CA, mid-1950s (Herb Cearley) PE 5119 again, this time in Los Angeles, mid-1950s (Herb Cearley)
Look at all that trolley wire. Such a spiderweb... Are they crossing their own line, or that of another operation?
PE "Hollywood" 5118 at Watts, CA, mid-1950s (Herb Cearley) PE Express Motor 1498 (former Coach 881) at Travel Town in Los Angeles, mid-1950s (Herb Cearley)
PE Blimp 306, Long Beach, CA, mid-1950s (Herb Cearley) PE Steeplecab 1624, West Hollywood, CA, mid-1950s (Herb Cearley)