About Mars Light

[ETR_500]

Dear railfriends,

I'm interested in learning something more about the "mars light", which, for an european railfan, is literally very odd. What function mars light has in US rail signaling? When it was introduced for the first time? Why that strobing/rotating characteristic? Some steam locomotive had mars light too or hadn't?

Thanks for your kind answer. 

[KCSfan]

The mars light was basically an adjunct to the regulary locomotive headlight. It circled (not quite the right word but the best I can think of) in a figure 8 pattern. They were common on early diesel locomotives, particularly passenger engines, and their purpose was to warn motorists and pedestrians of the approach of a fast train. I believe the Southern Pacific's Daylight steam locomotives and probably some others had mars lights. The observation cars at the rear of some passenger trains had a red mars light. I don't recall if these operated continuously or just when the train was stopped as a warning to oncoming trains.

Mark

[Poppa_Zit]

The Mars light (so named after the company which manufactured it, the Mars Signal Light Company of Chicago) was in its time -- and still is -- an absolute attention-getter. Much more so than a standard locomotive headlamp. It was created in the 1930s as a warning device for fire apparatus -- its inventor was a Chicago fireman who began by attaching a windshield wiper motor to a spotlight so he didn't have to manually sweep the road while trying to drive.

It was quickly adapted for use in the railroad industry.

Above is an animation of a Pyle GyraLight.

"The Light From Mars" as the manufacturer's plate said pierced the night sky with a narrow finger of brilliance, its dramatic side-to-side figure-8 sweeping motion illuminating areas 100 yards to either side of the tracks. When attacted to the front of a speeding train or vehicle, it was hard to ignore or mistake for something else, and thus the secret to its success.

Mars' "TB8 Traffic Buster" had a tremendous popularity on emergency vehicles in the days before the light bar made its debut. We had these lights (clear lenses, like locomotives) on the noses of our fire engines, and the view from the driver's seat at night was better because not only did the sweeping "888" better alert traffic we were coming, but it also gave us a better (wider) view of what was on each side of the road ahead. The FD version moved back-and forth (L to R) while gyrating in a figure 8 -- top to bottom, just as you see the number here. It was nicknamed "888" because during each sweep from right to left (and back) it made three distinct figure-8 motions. They were available in 60,000 and 100,000 CP versions. I can't speak to the CP of the ones used by locomotives.

The vehicle versions characteristically had a sealed-beam lamp that fit into a movable housing pivoted by a motor. On locomotives, however, most were of a design using a bulb and parabolic reflector -- and a motor oscillated the reflector behind the bulb, which was screwed into a fixed recepticle. In other words, the relector moved, but the lamp didn't.

Mars was dissolved in the 1990s, but another company is still producing the light for emergency vehicles.

They were really cool, and I have a working 888 (12v) salvaged from a retired pumper.

PZ   

[tree68]

There was also the Pyle "Gyralight", which I think may have simply described a large circle with its beam.  The effect down the tracks was about the same, however.  If you see film or video of either in use, you'll remember it.

There were both single and dual lamp versions.  Some railroads, like SP and ICG, had an array of lights on their locomotives, including fixed headlights and both red and clear oscillating lights.

Some railroads would put a clear and a red lens in a dual lamp version, lighting only the appropriate bulb.

[Modelcar]

 

.....Years ago I use to watch the Sante Fe Passenger trains arrive in the town of Kingman, Az and some of them would arrive at night and I can confirm they really caught one's attention...Before they arrived at the depot station platform....The red light would shine in the figure "8" pattern, on the trees, buildings, track and what not and it would get one's attention.

[Poppa_Zit]

Tree68 --

The gyrating light mounted on the smokebox of the Milwaukee Road 261 has a red lens.

I have always wondered -- while red may signal "emergency" -- it also is a difficult color to see from a distance than white (clear). Blue is even tougher for the eye to distinguish (that's the extent of my color-spectrum knowledge).

When I was a fireman, we used a blue light on our dashboard (or in the passenger compartment) when responding to a call when off-duty. Other cars could never see the blue light spinning on my dash in daylight -- so I added an alternating  flasher to my bright lights. That really cleared the way.

PZ

[Poppa_Zit]

 

.....Years ago I use to watch the Sante Fe Passenger trains arrive in the town of Kingman, Az and some of them would arrive at night and I can confirm they really caught one's attention...Before they arrived at the depot station platform....The red light would shine in the figure "8" pattern, on the trees, buildings, track and what not and it would get one's attention.

In Chicago, on the Racetrack, the Burlington's trains used white -- and on a dark night, it was spectacular... Metra still uses them today, but they don't see to be quite as bright as I remember on the CB&Q.

I think the 888 on the fire trucks was so successful because -- as you say -- it swept across trees, light poles, buildings -- creating dramatically moving shadows as well as lighting those elements. People aren't used to seeing dramatic movement in those places, ergo -- you command their attention. 

[Modelcar]

 

.....Yes, the shadows did add to the dramatics....!

[Poppa_Zit]

 

.....Yes, the shadows did add to the dramatics....!

Even on the cab roof of some locomotives (and fire trucks) with rotating beacons, often one of the three or four sealed beams was pointed not parallel to the road like the others, but at 45 degrees, to illuminate anything overhead and create said dramatic shadows. 

[Modelcar]

 

....The Kingman, Az. experience {1969-1970}, was my first exposure to them and the first time I witnessed one coming in I was kinda shocked as I didn't know what was going on....Attention getter....is putting it mildly.

[tree68]

Tree68 --

The gyrating light mounted on the smokebox of the Milwaukee Road 261 has a red lens.

I have always wondered -- while red may signal "emergency" -- it also is a difficult color to see from a distance than white (clear). Blue is even tougher for the eye to distinguish (that's the extent of my color-spectrum knowledge).

When I was a fireman, we used a blue light on our dashboard (or in the passenger compartment) when responding to a call when off-duty. Other cars could never see the blue light spinning on my dash in daylight -- so I added an alternating  flasher to my bright lights. That really cleared the way.

PZ

Volunteer FFs in NY still run blue, but that may be an endangered species, as the State Police are now running blue on the back side of their vehicles.  White (and now clear strobes) is very popular.  Adding flashing headlights to your blue light here will get you a ticket....

Blue beats out red at night, but as you say, it's hard to see during the day.  That's one reason so many police agencies run both red and blue, and many add white.  White is required on ambulances, however it's only supposed to be active when the tranny is in drive.

Without knowing how the red on the front of 261 was normally used (ie, running down the road or as an emergency signal), I can't speak to that.  Most apps I'm familiar with used red only as a warning that the train was stopped. 

I recall some years ago seeing a picture of a locomotive (Rutland or VT) with a red Beacon Ray running on the roof.  I think it was used the same way as the ambers that a number of railroads had installed.

Emergency lights are a fascinating study. I was in Maryland last fall.  The local volunteer FD has Buckeye "Rotorays" mounted on all of its apparatus, with one each red, white, and blue lamp....

Many of NKPs Berks had oscillating lights.

[Poppa_Zit]

Adding flashing headlights to your blue light here will get you a ticket....

It is illegal in Illinois on non-emergency vehicles, as well.

But the cops always bought the argument (wobbly legal legs) that our personal vehicle became an emergency vehicle as long as we were responding in it. We always had a good working relationship with 99 percent of the officers in each town we served, and I suppose we got a *wink* on it as a professional courtesy. It's hard to contest the argument that it increased our level of safety en route to an alarm.

Most of the guys were "quick-but-careful" drivers, and adjusted their response speed to the nature of the call. We just snuck over the speed limit for an automatic alarm at one of the "regular" false activation sites; on the other hand, it was foot hard to the floorboard if we were responding to call for a child choking.

  

[jchnhtfd]

They surely are attention getting!  No argument there, and one wishes they still existed as a routine ornament.  However... at least part of the situation, for railroads at least, was they were also a maintenance headache (not a nightmare, but a headache...).

 My memory ain't what she used to be, but I seem to recall that at least on some roads the light was white, except under braking (I think emergency braking) when it went red, to help warn anyone coming on another track that you had gone into emergency and that there was a finite chance that you were blocking the other track.  Sort of a handy automatic extension of the rule that said you had to send out a flag anytime you went into emergency in both directions, to warn the opposition.

[WSOR 3801]

The red oscilliating light would come on in an emergency application.  Helps warn oncoming trains in multiple track territory that something is wrong.

The FRA says that historic engines equipped with oscillating lights do not need ditch lights installed.  WSOR 10A&C have Gyralites, so full speed ahead with it on.  Between crossings, the light can be made stationary, which makes life a little easier.  Now to get them to let me run the E-units in the lead up the CN someday...

[AntonioFP45]

Amtrak's SDP40fs were equipped with Gyra-Lites.  White on top, red below it.  The red came on when emergency brakes were applied ( and I think when the locomotive was backing up ).

I used to enjoy watching these locomotives back in the 70s.  At night, the Gyra light's beam could be seen bouncing off of buildings in a cirbular pattern.  I was disappointed when most Class 1 railroads phased out these lights during the 80s.  Understandable from a maintenance view, though, as they were expensive to maintain. 

I've read on a forum post that one of the original Santa Fe FP45s at a museum is in running condition, and its Gyra Light restored.  Anyone know about this?

 

[CNW 6000]

Here's a thought-is there any correlation to the removal of the Mars and an increase in traffic vs train accidents?

[AntonioFP45]

From what I've read on the web regarding railway safety, ditch lights that can also flash for grade crossings are the modern day replacements for Mars and Gyra lights.   Though expensive, they're supposedly much cheaper to maintain since they are operated by electricity only and have no moving mechanical components.

[wjstix]

Didn't "Classic Trains" have an article on this about a year ago?? IRRC, the light was invented by a railroad worker who worked with Mr.Mars to get it on the market. BTW the Mars Co. that made the gyrating lights was owned by this same Mr. Mars, he also owned the Mars Candy Co.

[Poppa_Zit]

Didn't "Classic Trains" have an article on this about a year ago?? IRRC, the light was invented by a railroad worker who worked with Mr.Mars to get it on the market. BTW the Mars Co. that made the gyrating lights was owned by this same Mr. Mars, he also owned the Mars Candy Co.

Not railroad worker. Chicago fireman, Jerry Kennelly, for use as a spectacular lighting effect on fire apparatus to alert motorists (read above posts). Frank Mars, owner of the Mars Candy Co., financed the company that manufactured them. The were first adapted to railroad use in the CNW Proviso Yard, which is not far from the Mars Candy factory.

"The first railroad application was to a C&NW 4-6-2, number 2908, for
experimental/demonstration purposes in April 1936.  After some successful
trials, there was some other railroads that expressed interest.  Among the
first was J.D. Farrington of the Rock Island for the new Rocket trains.  He
arranged an introduction to William Otter and Richard Dilworth (Chief
Engineer) of EMD.  While Dilworth was skeptical, Farrington allowed them to
remove the front door from engine 604 which was currently being constructed
(601 to 603 were apparently already complete.)  They took the door to the
Mars factory in Oak Park and rigged up the first Mars light on a train.  Oak Park
Cadillac fixed up the paint and the door was returned."

BTW, the Mars light traveled in the 888 pattern while a Gyra Light was in an elliptical pattern, as tree68 has already pointed out. 

[Modelcar]

 

..........Interesting info....Unusual combination of the connection to Mr. Mars with his light and famous Mar's candy bar....

[Poppa_Zit]

 

..........Interesting info....Unusual combination of the connection to Mr. Mars with his light and famous Mar's candy bar....

[Modelcar]

 

........Neat....!   I'm surprised of the 12 volt usage...Thought railroad equipment used a different voltage than the usual 12 v.

[jcitron]

I wonder if they haven't thought of using LED arrays like the current rescue equipment have now. I noticed this when I was in traffic tonight. There was a MA State trooper car sitting next the disabled vehicle that caused the gawk-effect traffic jam. These can be pretty bright at night, as well as directional. Being totally electronic, they can be computer controlled to come on in any pattern they are configured for, and they are much easier to maintain then the older mechanical devices.

Thanks guys for the very informative history behind the Mars Light.

 John 

 

[Modelcar]

 

....Those LED lights are a modern marvel.  All kinds of them coming on the scene now.  From traffic lights, Bank "time and temp" signs, even flashlights and it's my understanding they use very little current.  A brand new Bank type sign we drive past quite often is unbelievably bright even in daylight.

They really should be a natural to use in emergency type lighting....Or warning lights.

[tree68]

 

They really should be a natural to use in emergency type lighting....Or warning lights.

And they are.  Check out that "almost stealth" lightbar on the next cop car you see.  A neat feature of LEDs is that they can have a clear housing, yet still project whatever color they are made for.  I have an LED dash light that shows no colors until you turn in on.  Then it flashes red and white.

As you can see from the many LED traffic lights that are around these days, LEDs can be added to make about as big a warning light as you care to create.

Even school buses are using LEDs now.

LEDs are getting popular in cars, particularly for stop and tail lights.  They've taken the trucking industry by storm.

I wouldn't be too surprised to see LED array ditchlights one of these days.  The catch is that they are great for a warning light, but they don't make very good headlights.  Have yet to see a vehicle with LED headlights....

[tree68]

This particular light was probably used on a fire truck (notice the chrome...).

The model "888" refers to the pattern the light "drew".

[Poppa_Zit]

 

........Neat....!   I'm surprised of the 12 volt usage...Thought railroad equipment used a different voltage than the usual 12 v.

They might. The one pictured is a Mars 888 mounted in a chrome bullet-shaped housing for exterior use on a fire truck. The also made flush mounts ... and still do. Click the image to enlarge & read specs...

 

[jcitron]

 

They really should be a natural to use in emergency type lighting....Or warning lights.

And they are.  Check out that "almost stealth" lightbar on the next cop car you see.  A neat feature of LEDs is that they can have a clear housing, yet still project whatever color they are made for.  I have an LED dash light that shows no colors until you turn in on.  Then it flashes red and white.

As you can see from the many LED traffic lights that are around these days, LEDs can be added to make about as big a warning light as you care to create.

Even school buses are using LEDs now.

LEDs are getting popular in cars, particularly for stop and tail lights.  They've taken the trucking industry by storm.

I wouldn't be too surprised to see LED array ditchlights one of these days.  The catch is that they are great for a warning light, but they don't make very good headlights.  Have yet to see a vehicle with LED headlights....

Funny you should mention the "stealth" lightbars. These bars are also thinner to then the old type so people think these are ski racks (being in the north), and not cop-lights on an unmarked car.

The LEDS are really amazing devices, and these new high intensity ones are really bright. I was wondering about this too, and a quick search on google produced this even though it is mentioned for automobiles, I'm sure the development could be for any transportation equipment:

"...headlamp applications using LEDs are not yet in volume production, but have been undergoing very active development, and present prototypes give performance roughly equal to existing halogen headlamps. These prototype designs currently require large packaging and a large number of the most powerful LED emitters available. As LED technology continues to evolve, the performance of LED headlamps is predicted to improve to approach, meet, and perhaps one day surpass that of HID headlamps. LED headlamps, foglamps and other forward illumination devices have so far generally been featured only on manufacturers' concept cars, but the first series-production LED headlamps will be factory-installed on the 2007 Lexus LS 600h / LS 600h L. They will also appear on the version of the 2007 Audi R8 sports car sold outside North America.

The limiting factors with LED headlamps presently include high system expense..."

Source: http://en.wikipedia.org/wiki/Headlight

Unfortunately the author did not list his references, but the last line says it all - the cost.

John 

[nbrodar]

The issue with using LEDs in railroad applications, is that 49CFR sec 229.125 states that locomotives headlights and auxiliary lights must produce 200,000 candela.  Currently, and for the near future this is beyond the reach of LEDs.  Anyone know the regs for automobile headlights?

However, LEDs are successfully, being used in EOTs, and Blue Flags.

Nick

[tree68]

Unfortunately the author did not list his references, but the last line says it all - the cost.

I can get a perfectly servicable halogen or strobe lightbar for my vehicle for around $1000, and certainly less.  Despite the fact that the cost of LEDs has come down, the full sized lightbars are still in the $2000+ range. 

But, boy, are they bright!

Because LEDs are (at least compared to incadescent/halogen) "instant-on/instant-off" it's possible to mimic strobes, halogens, and to get creative with flash patterns. 

IIRC, locomotive "auxiliary lights" (ditch lights) can be strobes.  I wouldn't be surprised to see someone try LEDs there, perhaps with a funky flash pattern.  Anything to attract attention!