Strobes?

[V&AL]

Besides usage in remote control, what is the purpose of Strobes/Rotary Beacons on locomotives? Does the color mean anything?

The 2 uses I come across on most are dual white strobes on older Amtrak units, and a single yellow strobe or rotator on BN road units.

When would the strobes be used?

 

[diburning]

The strobes would be used in the 70s to 80s before ditchlights were a federal requirement sometime in the 1990s.

 

[malletman]

BN used both the Western/Cullen rotary beacon, but the motor brush noise interfered with the early smart EOT's, so they switched to the huge 4 bulb electrionc beacon made by Prime. CNW had the W/C beacons and Tomar amber strobes, Amtrack used twin single pulse strobes on their F40's, EJ&E has red strobes on thier units. The filled the need for a less maintance intensive safety device before ditch lights came into being on USA railroads, the Europeans have run the tripple headlights since the era of Steam. I still then the Mars and Gyralite's of years past are a better safety light than any of the current stuff. Anymore the ditchlights just blend in with the headlights, the flashing while a little attention getting, is nowhere as effective to my eyes as the ocilating mars light or gyralites. Not only did they flash in your eyes as they traced thier path ahead of the locomotive, but you gained the sky effect as they flashed their beam off the trees, haze in the sky at night ect. Two of the local engines for the transportation museum have no ditch lights, but instead one has a twin beam Mars light (NKP GP7) and the other has a Pyle Gryalite (ex Milw Rd F7A) in its upper headlight casing. There ex UP GP 9 has ditch lights, I notice the previous two comming long before the ditch lights get my attention. But the big RR's look at the bottom line and ditch lights bascily have no maintance other than burnt out bulbs, Mars and Gyralights have motors and linkages that need greased, strobes and beacons are susctable to tree branch strikes being up on the roof, they get plastered with snow or diesel soot and become hard to see, and you cannot see them over the blinding headlights, so they are really only effective from the sides or rear. There are several makers of strobe circuits for non DCC users, most better decoders have the light effects programed in to them. Cheers Mike

 

[UP2CSX]

Amtrak continues to use white strobes along with ditch lights because studies have found that the strobes catch a driver's attention long before the headlight does on a fast moving train. Having them mounted on both sides of the cab assures that drivers coming from any direction will see at least one strobe.

Any locomotive that crosses a public roadway at speeds greater than 20 mph must have what is properly called "crossing lights", although we commonly call them ditch lights. Ditch lights were first used in Canada after landslide into a ditch covered enough of the track to derail the train but was not readily seen in the headlight, since the landslide was on a curve and the headlight was angled in the wrong direction. The CP started installing lights on the pilot angled so they illuminated the sides of the tracks out to about 400 feet. Ditch lights are not mandatory and very few roads outside of Canada actually have them.

Crossing lights are mounted so they form a triangle with the headlight at the top. They are pointed horizontally down the racks at a zero degree angle. Contrary to common belief, there is no requirement they flash if they are left on steady burn at all times. The only time they have to flash is if they are dark until the engineer sounds the horn. Then they must flash at least 40 but no more than 160 alternating flashes per minute.

Mike, I like the look of Mars and Gyralites too but, FWIW, the FRA did a study in the 80's about grade crossing warning signals and found the gyrating lights actually confused drivers, especially at night, when they consistently misjudged the train as being further away than it really was. They found the triangular shape of the crossing lights and the headlight not only attracted attention better but the driver were accurate in judging the distance of the train from the crossing. Getting rid of gyrating lights didn't cause the railroads any tears since they were expensive to buy and maintain but there is some good science behind the advantage of crossing lights over gyrating lights.

 

[BNSF dude]

There is proof that Rock Island Railroad used a form of flashing ditchlights before anyone else. I cannot find the photo, but a few of their U-Boats had two headlights mounted above the cab on each side, they would flash alternatively according to a friend of mine's dad who envied the RI before the bankruptcy.

 

[UP2CSX]

You mean like this?:

The Rock started to experiment with flashing roof mounted lights sometime around 1970. As you can see, they certainly weren't what we'd call ditch lights, or crossing lights, today. The experiment seemed to last until about 1975 or so, when the lights were removed. They were tried in steady burn, dual flashing, and alternating flashing modes. I've never read anything official about any testing but I suspect the additional lighting just blended into the headlight and didn't provide much in the way extra warning power.