Watched a video today about steam Locos. {Last Of the Giants }They said something about filling some Engines with steam in the round house and burning some tires in the boiler to look like it was running,then pushed with another engine for the show.Why the steam?.Why not just fire it up.Thank you in advance
thats a good qustion maybe cuz tere to old?
Because the locomotive did not have a valid FRA boiler certificate. The cost of the necessary testing, even if no repairs were necessary was more than the film makers were willing to pay. If the flue time had expired, then the cost would be very expensive.
What a brilliant idea!!! That way you can warp all the firebox sheets and probably triple the cost of repairs!!
The question i really wanted to know,why the steam is added,just to show a little steam escaping and dont know what the third poster means.
Using an external boiler to add some steam to the locomotive is done for a couple of reasons. You caught the first one - to show a little steam escaping. But the second reason is also important, warming the boiler up sufficient to allow a little steam to escape heats up much of the metal, expanding it slightly and loosening up all the sliding tolerances. That is particularly important for the cylinders and valves. Warm metal also lubricates easier. Cold rod oil has about the same consistancy as cold molasses! and is almost as effective a lubricant;).
Many times the rods are removed when a dead steam locomtive has to be moved any distance. That is another way of solving the cold lubrication problem - but is not nearly as impressive in a video.
Any boiler has to be certified to operate a working pressure as a public safety issue. There are many levels of inspection and testing to certify a boiler, depending on the elapsed and operating time (flue time) since the previous overhaul. Most US steam locomotives were operated until the next inspection was due before being retired. Thus, every boiler being restored also needs recertification. Among the tasks that are part of recertification are reoving the casing and lagging and measuring boiler metal thickness at specified intervals (every 6" and every 12" are common patterns). All of the valves and injectors need to be rebuilt and tested. All of the gauges and pressure release valves need to be recalibrated and recertified, etc. This is time consuming and very expensive.
Finally, the comment about a hot tire fire warping firebox sheets is true. Any spot heating of a cold firebox or boiler can cause damage. However, if the boiler has been warmed by an exte