Volts X Amps = Watts

This is what I want to know.  Everyone agrees that 360 Watts (2 x 180 Watts) is greater than 32 Watts (40 bulbs at 0.8 Watts each).  What is/was the hookup that causes bulbs to fail after 30 minutes?  Bulbs like these should have an average life measured in the thousands of hours.

Stan, I'd suspect the bulbs aren't actually rated for the voltage from the transformer.  If you put a 12V bulb on 18 volts, it'll last... maybe half an hour?

Lee, FWIW, the 1940's Lionel manual "Model Railroading" said to figure 5-watts per 18-volt bulb.

Nope. These bulbs are .8 watts each and they are running at 14 volts with a transformer rated at ten times what they draw.

Then they "quit working" after a half hour. One thing not clear, are they burning out or just quitting until the transformer gets reset and then they light up for another half hour?

First, many people here have encounter Christmas-tree light strings, or the occasional lamp socket, that intermitantly goes off by itself after a few minutes.  Somewhere in the circuit, a connection is heating up and as it does metal expands and what was a barely-marginal contact when the metal was cold is now open.  This would be my guess, actually.

Second, and I really don't think this is the case, but  . . . I know nothing about bricks, but some power supplies will go over voltage - too high - when not loaded sufficiently.  

I recently burned out a .7 watt T4 12V LED (.06 amp at 12 V) I was installing in a building and  testing using Bachmann power back (below) rated 16 Watts at 16V output.  No big deal, but very surprising.  I twisted the knob to about 3/4 around to get what I thought would be 12V and tested the LED, which lasted about a minute.  

When it failed, I then measured the power pack's open-circuit (no load at all) voltage atthat throttle setting (knob 3/4 around) and it was close to 18V - no wonder it died.  I turned the knob all around to check, and unit's output at full throttle postion and no load was 23.8 volts or nearly 50% higher voltage than its rating.  

Now obviously voltage will drop as any load is applied but: I tested another LED (they are cheap)for a moment and at that same three-quarter-around-should-give-12V setting, I was getting 16V even when feeding this tiny (about 4% of the supplies rating) load.  I would think Lionel bricks would have beeter voltage regulation that this.  However, this is something else to consider - 10% or less of rated output, can result in some power supplies putting out too much voltage.  You might actually measured the voltage right at the time it goes off,if you have not done so at that time . . . 

Paul, Are all the lights on one terminal of the ZW-C?  When you have 2 bricks installed with the 2 Jumpers, A&B run off one brick and C&D run off the other.  There is no sharing between the 2 bricks unless you placed half the lights on A or B and the other half on C or D.  G

Hmm, now I wonder if the two 14V outputs are/were wired in series.  If you put 18V bulbs on 28V...