Hi I came a cross this sign on Barstow Yard does anyone know what it means ? 47103F0B-0062-4CB5-923B-873F33DD08CD by fietsbel12 posted Sep 18, 2022 at 7:28 PM
It might refer to a derailing device on the track ahead to prevent collisions from loose rolling stock or a train on the wrong track.
Thanks everybody this is what I have found thanks to breblimator. For someone not fermiliar with trains this is a bit technical can someone explain it in a simple way ?
Simply put, a railroad must sometimes choose between a deliberate derailment which may cause material loss or a more serious collision which may endanger train personnel, passengers or the safety of ROW crews.
it means that you leave the classification and enter on normal circulation. and yes "danger" is correct.
To elaborate on what has already been written here... The D sign is to mark the location of a derail. A derail (pronounced DEE-rail) is a track structure that is designed to derail any engines or cars/wagons that go over it. Derails are used to protect men and equipment, and to protect main lines. For example, you would not want a tank car full of denatured ethanol sitting on an industrial track to have brake problems and roll by gravity onto the main line and run loose and out of control for who-knows-how long until it hits something and explodes. The derail forces the train or cars off the rails before it gets too out of control. There are temporary and permanent derails, and there are two main designs. The purple D sign above with the blue Men At Work sign is a flange-lift derail. The presence of the switch stand indicates it's permanently installed on the track. The only thing that keeps the trains on the rails are the flanges on the insides of the rails. This type of derail picks up the one flanges and moves it out of position to come off of the rails. Derails of this design can be portable and clamped onto the track as needed, too. The other design of derail is one that looks like a turnout, or track switch. But, the diverging rails are mostly missing, so when in the "derailing position," the engine or car/wagon is carried right off the rails and into the weeds. This type is always permanently installed.
Actually, that's a different mechanism - though with a similar effect. As the photo shows, a derailer is a device that sits on top of one of the running rails, physically lifting and pushing wheels that roll over it across the top of the rail. The opposite wheels would then fall off the other rail, into the four-foot. Catch points are just an abbreviated siding - often abbreviated so much as to not reach the crossing nose - constructed from at least part of a normal set of points. Rather than lifting the wheel so that the flange passes over the top of the rail, it is diverted through a gap. Or, in the case of a wide-gauge trap, through two gaps, effectively wedging the running rails between the backs of the flanges.
For another note... this photo also depicts blue flag protection. The blue MEN AT WORK sign and blue light indicate that this track and the equipment beyond it is under blue flag protection. Such equipment cannot be started, moved, coupled or attached to, etcetera, until an employee of the class or profession that placed the blue flag removes it/them. This protection ensures that people who maintain or sleep in rail cars are not injured doing such.
