Rear emergency lights on utility body

[Notabombtech]

hello, I've been lurking on the forum for several weeks now and have already learned a tremendous amount of information. we are purchasing new trucks at work and the rear body will be an enclosed service body similar to a construction/ plumbers style truck. These vehicles are for responding to emergencies only and will not be used for traffic control or traffic stops. We've chosen 4 Whelen M4's for the rear of they body and they will be placed high and mid level. From what I've read about split fail, flash speeds and lighting locations I've determined that 2 of the lights will be solid blue and 2 will be solid red. My question is should both red lights be placed on one side and both blues be placed on the other side or should they be placed in an X pattern. Keep in mind that they blue and red will not flash simultaneously to avoid the purple blob.

TLDR; 4 Whelen M4's on rear of body 2 red 2 blue, x pattern or same side.

Thank you in advance everyone!

 

[dcb]

My suggestion: Driver Side Red, Pass Side Blue, using an x-pattern

 

[Notabombtech]

Sorry for the confusion, to clarify would both lights of the same color be better on the same side or criss crossed keeping in mind that only one color will be lit at any time

 

[CHIEFOPS]

Are 2 colors required for your application?

 

[Notabombtech]

Are 2 colors required for your application?

Yes, it is a police department vehicle and red and blue are the PD colors in my state

 

[Jarred J.]

You could also go top to bottom.

 

[CHIEFOPS]

If I had to display 2 colors and the vehicle was not intended to perform a blocking function I'd run all 4 across the top, blues outboard/red inboard and alternate outboard/inboard at 75 or 90 fpm

 

[Notabombtech]

due to the way the body is designed placing all the lights across the top isn't an easy option. And as far as not being intended to block traffic or being used to stop vehicles, its definitely not a daily activity but will happen occasionally until a marked car arrives. the top two lights are Whelen M4DW Scene/ Emergency combo lights that will double as back up and scene lighting. The bottom two will be straight M4's without the scene light combo. If I've read correctly the goal is to have only a single color flash at one time to prevent a purple blob.

 

[dcb]

Sorry for the confusion, to clarify would both lights of the same color be better on the same side or criss crossed keeping in mind that only one color will be lit at any time

Driver Side Red (Upper/Lower), Passenger Side Blue (Upper/Lower), using an X-pattern

 

[Notabombtech]

Driver Side Red (Upper/Lower), Passenger Side Blue (Upper/Lower), using an X-pattern

just curious, why don't I want both red lights to flash at the same time then both blues? I'm not sure im tracking what you're saying

 

[Doyle257]

just curious, why don't I want both red lights to flash at the same time then both blues? I'm not sure im tracking what you're saying

I would Flash red, then flash blue. if you mix the 2, you'll end up getting a splitfail purple.

For any vehicle that will spend any amount of time parked in traffic, I would suggest High, medium, and low heights. From what your application sounds like, im going to venture that while the vehicle may not be used in traffic stops, it may be on a scene, in front of a building, which would cause it to be blocking a lane of traffic?

 

[Notabombtech]

I would Flash red, then flash blue. if you mix the 2, you'll end up getting a splitfail purple.

For any vehicle that will spend any amount of time parked in traffic, I would suggest High, medium, and low heights. From what your application sounds like, im going to venture that while the vehicle may not be used in traffic stops, it may be on a scene, in front of a building, which would cause it to be blocking a lane of traffic?

Generally no. once we're on scene we are usually well within a perimeter and generally wont be blocking a lane of traffic. on the rare occasion that we are blocking traffic it's generallt for a short perior of time until a marked vehicle arrives. I'm in agreement in regards to the purple blob split fail, I think I'm not wording my question correctly. The front of the vehicle will be equipped with Whelen inner edge lights, 4 whelen ions in the grill, vertex led strobes in the headlights, whelen ions mounted on the mirrors, ion's mounted above the front fender, ions mounted above the running boards, and two M4's mounted on the side of the body (high). the height of the body is just above the cab of the truck, and it is a single rear vehicle. the back will have 4 M4's
(2 red, 2 blue) mounted at the top of the body, and then mounted lower middle just above the turn signals and stop lamps.

Based off what I've read on here, all red emergency lights on the vehicle will flash at the same time, then all blue lights will flash at the same time. keeping that in mind as far as the rear lights go should both red M4's be in a line on the drivers side and both blue M4's be in a line on the passenger side or should one red be top drivers and one red be lower passenger creating the "X" while the blue's do the opposite? at no time will both blue and red be flashing (to avoid split fail purple blob)

 

[SafetyLighting]

Your first drawing is how I would install them. Red top left and bottom right. Blue top right and bottom left.

 

[NPS Ranger]

For what it's worth, this is a pretty common arrangement in NYC:

 

[CHIEFOPS]

For what it's worth, this is a pretty common arrangement in NYC:

I never liked their abandonment of the 4 amber configuration

 

[firebuff17]

Like CHIEFOPS stated.
At least some amber would be nice.
I am a fan of the blue/amber combo.
2 heads blue 2 heads amber.

 

[Notabombtech]

Like CHIEFOPS stated.
At least some amber would be nice.
I am a fan of the blue/amber combo.
2 heads blue 2 heads amber.

in hindsight we should've spec'd a low profile traffic advisor but we're stuck with what we've spec'd. The lights have to be red and blue.

 

[NPS Ranger]

OK OK I get it.... for your viewing pleasure, scroll to 1:15 in this video:

 

[CHIEFOPS]

Way too much going on back there

 

[Doyle257]

OK OK I get it.... for your viewing pleasure, scroll to 1:15 in this video:

jesus....thats WAY too much...

 

[Notabombtech]

Okay so this is basically the exact set up we will have but with four Whelen M4's. two red two blue. I think I'm more confused than when I originally posted lol. The top two lights, regardless of color will be the M4's that also double as white scene light when selected (also come on white when in reverse). At this point adding any amber lights or additional lights is out of the picture and I'm just trying to figure out which pattern they should be in. Sorry for making this more difficult then necessary!

 

[firebuff17]

I would do blue high side and red low side.
Flash in an X pattern. They are far enough apart that they won’t create a purple blur.
Or you could do both high then both low.
As your aware, your going to get a hundred different preferences. It’s up to you.

 

[Jarred J.]

where do i put my quarter at for that comms unit...

the truck doesnt look bad, but everything needs to be slowed way the heck down

 

[dcb]

just curious, why don't I want both red lights to flash at the same time then both blues? I'm not sure im tracking what you're saying

Just my preference. I think it shows the vehicle profile better and there is always some activity on each side.

 

[StEaLtH2]

Personally,
top Red<>Blue
lower. Blue<>Red
Flashed in the good ole X pattern on a slow(single) to mild(actionflash or signalalert)pattern.

The combo lights, are they the V series?
Are you spec'ing color lenses.?.!.

 

[CHIEFOPS]

Restricted to red and blue, I'd go with blue high/red low flashing high vs. low 75 to 90 fpm

 

[Notabombtech]

Personally,
top Red<>Blue
lower. Blue<>Red
Flashed in the good ole X pattern on a slow(single) to mild(actionflash or signalalert)pattern.

The combo lights, are they the V series?
Are you spec'ing color lenses.?.!.

They are the M4DW Combination Driving/Warning Light, Red or Blue Warning with Scan-Lock™ Flash Patterns, Clear Outer Lens. it isn't the v model it is flat. thank you everyone for your suggestions and advice so far.