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Mars lights vs gyrolights

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Mars lights vs gyrolights
Posted by tstage on Monday, September 26, 2016 9:40 AM

I asked this as part of another thread but thought it better to post it here.

How easy is it to distinguish a Mars light and a gyrolight when they're coming at you from a distance?  Given the pattern, it seems to me that the flash of the Mars light (figure-8) would be twice as fast as the gyrolight (oval)?  Also, is there an advantage of using one type over the other?

Thanks!

Tom

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Posted by jrbernier on Monday, September 26, 2016 11:47 AM

MARS light - Early ones usually had the classic 'figure 8' light pattern.  The light was developed by the owner of Mars Candy for the Chicago Fire Depth.

Gyralite - Light pattern is a circular sweep pattern.  MARS also offered a circular sweep.

  Both lights used a mechanical motion powered by an electric motor.  And both were prone to grind up their gears - one of the reason many railroads gave up on them.

Modeling BNSF  and Milwaukee Road in SW Wisconsin

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Posted by mlehman on Monday, September 26, 2016 12:48 PM

Thought I read something recently that noted, beyond the mechnical issues, the thing that really killed them off was that such lighting was not part of the FRA mandates that put dicth lights into effect. Beyond the cool factor, RRs went to the expense of such lighting for legal reasons, as it helped establish the RR did all it could to prevent accidents at grade crossings. That's why some saw the expense as worth the investment in such lighting.

Once there was a federal standard, this satisfied the same need. Besides that, it was required. Didn't make sense to continue maintaining another lighting system independently of the required one that now satisfied the nationwide legal requirements for train lighting.

Mike Lehman

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Posted by wjstix on Monday, September 26, 2016 1:00 PM

Mike, you might be thinking of the rotating beacon lights that railroads started mounting on the roofs of diesels in the 1960's. Those were generally removed after the Canadian-style three light "ditch light" was required in the 1980's or 90's. Mars lights and Gyra-lights were created in the 1930's for use on the then-new high speed streamlined passenger trains. After Amtrak in 1971, private railroads normally weren't running passenger trains, so didn't need Mars lights on any engines. Those few railroads that did run passenger trains (like BN commuter trains in Chicagoland) were using rotating / strobe lights on the roof.

Stix
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Posted by mlehman on Monday, September 26, 2016 2:10 PM

Stix,

Actually, whatever I was reading mentioned them, too, as falling under the same economic and legal pressures. It's not that their removal was dictated or anything, it's just that the cost no longer made sense in effectively duplicating what the bean counter and lawyers knew they were required to support.

The article did point out that the mechnical issues had already made Mars and Gyralite lose considerable ground prior to this, unlike roof beacons that didn't have such extraordinary maintenance costs and were more widespread when the ditchlight mandate came into effect.

Yes, lots less need after 1971 in terms of pass ops, but many road used these lights on freight locos, like the Rio Grande. As I recall (and I'm not doing real well here on the details like what I was reading...Stick out tongue ) the Rio Grande kept theirs operative until they bought SP and new management came in (>late 80s?). Jim F. may know, as his interest is in that era, whereas I'm mostly NG-oriented.

Mike Lehman

Urbana, IL

NDG
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Posted by NDG on Monday, September 26, 2016 4:49 PM

 

Thank You.

 

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Posted by gmpullman on Monday, September 26, 2016 5:14 PM

Hi, Tom

I have had a long-time fascination for the oscillating headlights.

From a modeling standpoint, when observing the on-coming train, the eye would interpret the Mars light as two closely spaced "pulses" of light about once every second.

From Wikipedia:

A purely mechanical application of a Lissajous curve with a=1, b=2 is in the driving mechanism of the Mars Light type of oscillating beam lamps popular with railroads in the mid-1900s. The beam in some versions traces out a lopsided figure-8 pattern with the "8" lying on its side.

The Gyralight would appear as a single pulse about once a second.

Very minor differences but distinct just the same.

Saturday, I was fortunate enough to spend a few hours with the Nickel Plate 767 [nee 765]. I didn't shoot any video but this still photo shows how concentrated the light beam is on the Mars light:

The original Mars light was designed and patented by a Chicago firefighter for use on fire engines. Mars Signal Light Company was bought by TriLite and a similar model, the "Mars 888" is still produced today. Gyralight was a product of the Pyle-National Company and was purchased by Trans-Lite Inc. presently dba "Teknoware".

As far as why one was chosen over the other was purely a decision of the railroad's engineering, finance or chief mechanical officer. The Gyralite claimed simpler maintenance but that may be purely hype.

Regards, Ed

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Posted by mlehman on Monday, September 26, 2016 7:45 PM

Ed,

I think being steerable was another feature, maybe only on one or different between them? IIRC that being a feature that was liked on mountain RRs as you could illuminate curves a bit with it.

Mike Lehman

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Posted by gmpullman on Monday, September 26, 2016 8:59 PM

Mike,

So that's where Preston Tucker got his idea for the steerable headlight on the Tucker 48!

It would be entirely possible to have a "jog" button on the motor. I seem to recall a Mars operating switch that had something like an On-Off-Automatic setting for the motor drive. There were many models and I'm sure railroad electricians could make their own modifications.

Some railroads did use the dual red-clear lamps and a pressure switch tied to the brake line would automatically kick the "signal light" into an oscillating red mode, sometimes on the rear, too.

The Nickel Plate had Gyralights on passenger and freight but I didn't see them used on freight very often. Maybe only on their hotshot freight called the Flying Saucer! I made a red Gyralight for the rear of my NKP passenger trains.

I actually have the same model Gyralite on my own "caboose" here at home. The motor is wired through a relay in series with the lamp so that if the lamp burns out the motor automatically stops. A neat bit of engineering.

Just more of the neat little details that makes model railroading so very interesting!

Have Fun, Ed

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Posted by doctorwayne on Tuesday, September 27, 2016 11:13 AM

gmpullman
Saturday, I was fortunate enough to spend a few hours with the Nickel Plate 767 [nee 765].

Geez, Ed, I really wish that I had known that you were on that train, too. I was there with a couple of good friends from Pennsylvania and Ohio, both ex-railroaders.  I'll bet that there would have been some interesting tales exchanged. Smile, Wink & Grin

Wayne

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Posted by dti406 on Tuesday, September 27, 2016 12:39 PM

doctorwayne
 
gmpullman
Saturday, I was fortunate enough to spend a few hours with the Nickel Plate 767 [nee 765].

 

Geez, Ed, I really wish that I had known that you were on that train, too. I was there with a couple of good friends from Pennsylvania and Ohio, both ex-railroaders.  I'll bet that there would have been some interesting tales exchanged. Smile, Wink & Grin

Wayne

 

I wish I had known both of you were there! I only live a couple of miles away and drive down that road every day on my way to work. Here is a shot I took on my way to work after last years event.  The 765 was heading back home!

Rick Jesionowski

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