the MRH Forum

Reefer sound "cycle off"? Really? Doesn't seem right. Journals/Blogs
Reply
Regular poster 368 posts shoofly Regular poster 368 posts
shoofly
Way back in the 1990s Model Railroader published a DIY circuit for a reefer sound generator with a 555 timer, a pseudo transducer, plus a myriad of parts. It was powered by a simple 9 volt battery. As crude as this thing was. It sounded more like a clicker, you get 2 or more of these things together then it started sounding more like a refrigeration unit. It was kind of a cool effect and back then onboard sound in any sort of capacity was pretty unique. Fast forward to now, Athearn releases the 57' FGE reefer (much anticipated) with sound. The sound is vastly superior to the 1990s MR special buzzer in a box. I noticed other modelers installing sound in their other reefers to get the effect of the Athearn one. Now here's when things get fuzzy.... I don't EVER recall hearing a 1960s-1990s era PFE reefer generator "cycling off" as the Athearn model does. I'm not claiming Athearn is wrong, in fact I can't really remember the times I was railfanning listening to the FGE reefer running. I do remember the PFE, SPFE, UPFE 57' PCF reefers running and I don't EVER recall them doing the "cycle off" bit. I asked another modeler/real life BNSF engineer if he remembered those cars "cycling off" and he recalled the same, adding that he remembers them being always running. With Ring Engineering's pickup freight car truck, and ITTC's sound unit, the timing seemed right to add sound to my existing PFE Cold Block. I have a few recordings of running reefers and am going to vary the sound among the cars to avoid phase cancelation and to make things sound more realistic. Does anyone else have any memory to the reefer generator "cycle off"? Chris Palomarez
Reply 0
Joe Brugger Prolific poster 1,014 posts
Joe Brugger

Cycles

We used to see PFE cars sitting in strings of 25, 50, or more at the south end of the Pocatello, ID yard and the effect was one large hum.  Among that many cars, hearing one cycle on and off was probably imperceptible unless you were standing right next to it when it turned on or off.

My personal feeling is that the Athearn cycle is too short on-off-on-off but there doesn't seem to be a way to adjust it. If I bought 49 more cars, maybe it wouldn't be so noticeable.

Reply 0
Bernd MRH Author 5,587 posts
Bernd

Refrigeration

Think about your fridge at home. Does it cycle or run continuously? If it runs continuously you have a problem, means it isn't cooling. May not be the answer you're looking for but sounds logical.

Bernd

New York, Vermont & Northern Rwy. - Route of the Black Diamonds - NCSWIC
Reply 0
shoofly Regular poster 368 posts
shoofly

Point taken, but...

If the power went out, i would need a generator running all the time to provide electricity to the fridge. As I and a few others I talked to recall PFE reefers with generators running always on. Since freightcars don't have HEP, they need power to make the refrigeration run, right? Better wiki this I think.The PFE column this month got me wondering.
Reply 0
DKRickman Prolific poster 3,069 posts
DKRickman

Continuous, I think

The compressor may cycle, but the engine might not.  I can remember having to check the fuel level in mechanical reefers every time we humped one, and the engine was always running on a loaded car.  I don't think they were designed to shut down and restart automatically, the way modern refrigeration units are.

Ken Rickman

Danville & Western HO modeler and web historian

http://southern-railway.railfan.net/dw/
Reply 0
Joe Brugger Prolific poster 1,014 posts
Joe Brugger

More answers

A little more definitive discussion here: http://www.trainorders.com/discussion/read.php?1,3180325

Short answer: '70s equipment ran all the time, more sophisticated controls on contemporary equipment gives the reefer units two speeds of operation in addition to 'on' and 'off'.
Reply 0
locoi1sa Regular poster 310 posts
locoi1sa

Cost of fuel.

    The older reefers used to run all the time and the compressor cycled on and off as needed. When diesel fuel hit $4 a gallon everyone wants to save some money. Better insulation, instant on, and electronic control has saved millions in fuel costs. Better to start and run the diesel instead of idling it for hours while the compressor is not cycling. In the late seventies I pulled frozen foods out of Ohio and could burn up about 60 to 70 gallons of fuel just for the reefer in a 24 hour day. These new units would take a week to burn that much and still keep the load frozen.

             Pete
Reply 0
shoofly Regular poster 368 posts
shoofly

DIY PFE Mechanical Reefer Sounds

After receiving the feedback, I went to work editing and recording several sounds to recreate best I could from memory (I know I know, not very reassuring LOL). I recorded a decent engine sound then added a fan switching on then cycling off with the engine running continuously. Made this a loop and will try it out loaded onto an ITTC module. For tests, I placed a Red Caboose shell over the speaker on my laptop to hear how the sound reacts to being in a box. It certainly enhanced the bass, a little too much, still tinkering with a few sounds and see how it goes from here.

ngreefer.jpg 

 

The waveform on the second line is the fan switching on running for 30 seconds then switching off. The generator on the first line runs continuously as  a loop.

 

Chris
Reply 0
Prof_Klyzlr Moderator 7,956 posts
Prof_Klyzlr

Check RMWeb...

Dear Chris,

Good to see someone actually getting their hands dirty in an Audio Editor, doing some "sonic modelling".

Unfortunately, RMWeb beat you to this particular discussion by about 2.5 years...

http://www.rmweb.co.uk/community/index.php?/topic/28008-diy-mech-reefer-sound-unit-circuit/
(Admitedly, they were more focussed on the more-modern-era Cummins, Detroit, and Isuzu-powered fridge units, but the core concepts and how-to deployments are cross-compatible/applicable).

I'd suggest instead of the ITTC module, trying a cheapo MP3 player,

a Digitrax "Soundbug" or similar,
(contact Dr Geoff Bunza for info and how-tos!),

or even a Pricom DreamPlayer LITE.
http://www.pricom.com/Trains/DreamPlayerLITE.shtml

Hope this helps,

Happy Modelling,
Aim to Improve,
Prof Klyzlr
Reply 0
Reply