• Slugs

  • All about locomotive rebuilders, small locomotive works, and experimental works
All about locomotive rebuilders, small locomotive works, and experimental works

Moderator: Komachi

  by fglk
Conrail used to call there Yard engions Slugs and Slug Mothers Mother being a fully operational engion with the slug just tagging along.

Cow and Calf is anouther one for a yard engion operateing with a slug.

  by trainmaster_1
fglk wrote:Cow and Calf is anouther one for a yard engion operateing with a slug.
Technically that is wrong a cow and a calf is like comparing an F7A with an F7B its the same way as what it is called a cow(A - fully functional cab) and calf (B - Cabless unit, its just a booster unit).

  by sandpvrr
Hello All,
Think I'll provide some context for that comment I made - the New Brunswick Southern (NBSR) has a few dedicated yard switchers, I believe that some of them are the GP-9s they used to use on the road. Quite sure that two of them are SW1200s or something similar.
When I was chatting with a Canadian railfan friend, he said that they use Yard slugs in the yards - almost exclusively. When I asked if they had numbers, he replied that they did, and rattled off a few. I checked a NBSR roster, all the numbers that he supplied were self-powered fully functional locomotives. But the term 'Slug' was attached to them. I guess because they are restricted to yard duty, more or less.
I would take a guess that this is one of those terms that varies from railroad to railroad - switcher - shunter - goat - critter - are others I've heard attached to yard units. This is like what railroads called the caboose - crummy - van - buggy - same thing, different place, different RR.
For those that don't know - NBSR is owned by Irving, they bought the former CP Mattawamkeag Sub (Line from Brownville Jct. East) to St. John, and have picked up some other trackage from CN (a yard in St. John) along with some branches and other trackage. I know about the operations from Brownville Jct. to the Border, but not much else. I have been to St. John once.
Comments are always appreciated!
cya, Joey

  by fglk
Could a cabless remote control engion work with a Yard or Road slug?? Dose anyone run any??

  by sandpvrr
Hello All,
Regarding the above - In a word - yes.
In terms of the locomotive part of a Remote Controlled Locomotive (hereon referred to as a RCL) is virtually unchanged from a normal locomotive. The difference is the control stand is either modified, removed, or able to be cut out. In its place is a remote control system. If the unit is a mother (of a slug), the slug operation won't be effected by a RCL system, the RCL system is just a different method of controlling the unit.
I think I've seen a setup such as this switching a hump yard (not in person, on video or pictures) but I don't recall where.
Just as an FYI - up here in my neck of the woods, the Montreal Maine and Atlantic Railway (successor to the BAR) just build a RCL caboose - works like a remote unit, but communicates with a loco via the MU cabling.
Hope this helps!
cya, Joey

  by trainmaster_1
So has Montana RailLink, they have RCL cabooses as well I'm guessing its an easier set up because you can hook up any locomotive with the MU cables and use it in remote control for switching purposes.

  by missthealcos
I believe the terms cow and calf only officially related to early GM switchers(TR4 etc.) Did they actually refer to F-units the same way?

  by fglk
The Finger Lakes Railway has an RCL Caboose that they use in Solavy, NY at Solvay Paper Board.

  by sandpvrr
Hello All,
Regarding the comment above about F unit naming - I too believe that Cow and Calf were used exclusively on the SW (and NW as well?) series switchers.
I think the official designation of F units was Cab unit or Booster - what we commonly refer to as an A unit being a Cab unit and a B being a booster. This would also apply to the Alco FAs and FBs, along with PAs and PBs.
FGLK - regarding that caboose you mentioned - as per some information I recieved up here, the MM&A folks were going to go inspect that one that Finger Lakes has, but the trip never occured. It should be mentioned that while under Burkhardt control the Wisconsin Central had I believe 12 cabooses, all equiped for RCL operation. These, more than anything else I'm told, were the inspiration for the MM&A cabooses.
Trainmaster_1 - I agree, the RCL caboose concept works much better than a dedicated unit with an RCL setup. I have seen the MM&A's first caboose (numbered VB-1 for some reason) controlling a half dozen different locomotives, attesting to its versitility.
Have fun all!
cya, Joey

  by fglk
Hay one question sents were chatering about Remote Control here was it the Norfolk & Western or the Southern Railway that out fitted 40ft Boxcars with remote Control??

  by ACLfan
I'm not sure about the N&W, but the Southern Rwy had mid-train helper units that were remotely-controlled from the front-end diesel units via remote control cars made from converted 40-foot boxcars.


  by Typewriters
The name "cow and calf" was, as you say, applied to sets of switch engines which were originally semi-permanently coupled together by drawbars (instead of couplers) and which contained cab and booster units. I might add that both ALCO and Baldwin also built "A" and "B" unit switch engines in this same configuration as well; Oliver Iron Mining was a well-known user of such engines.

"Booster" units are locomotives without cabs. This term seems to have originated from the early products of EMC/GM wherein the "B" units did not have equivalent horsepower to the controlling, or "A" units. Some of the early Pullman-Standard and Budd passenger trainsets had, for example, a 1200 HP lead unit and a trailing 900 HP cabless booster. Later, of course, but not too much later, the cab and booster units became equivalent in power as we know them.

"Slugs," as I've always known them, are units with traction motors but without prime movers, receiving traction current from either one or two locomotives at a time. This is distinctly different from brake trailers, or brake sleds, which are simply cars (sometimes gutted and topped locomotives) attached to switch engines (or units being employed as switch engines, I should say) which are used to add braking power for quicker stops when switching. Because a brake sled is operated like a locomotive as far as the brake system is concerned (tied to independent, or locomotive brake) it adds braking power, even when air isn't used on the cars being switched. These also help avoid flat spotting of locomotive wheels due to locking up the brakes.

The ALCO-GE and Baldwin manuals here refer to road freight and road passenger locomotives as "A" and "B" units. However, the terms "cab" and "booster" seem to have been used very often by the railroads/railroaders at the time.

Finally, I always thought it humorous that the three unit C&O cow/calf/calf switch engine sets were referred to as "herds." Never was sure if that was railroad or railfan generated naming, but funny nonetheless!

-Will Davis

Are "slugs" only used in the warmer climate regions? I've never seen one in NY. Here in the northeast it is common to use salt to melt ice & snow. I've also heard that it's bad to put salt on a slug. Maybe that's why.