Railroad SLUGS
ฝัง
- เผยแพร่เมื่อ 5 ก.พ. 2025
- You've probably seen one before, but what does the railroad use slugs for and how did they get that name?
Follow me on social media!
Instagram: www.instagram....
Twitter: v1...
Flickr: www.flickr.com...
#documentary #railway #engineering
Slugs are created from locomotives that had accidents or spare parts. The old fuel tank is usually filled with Cement for adding weight back, from the now removed engine. They are different from Booster (B) units that have no cab but still have an engine.
@Kabuki Kitsune just wanted to ask if they couldn't do that :D
@Kabuki Kitsune was going to say this seems like the logical thing to do.
@@RandoWisLuL Most slugs _can't_ supply fuel to the mother. It requires relatively complex plumbing, and fuel hoses between the locomotives. The extra fuel store isn't very useful, as slugs are generally used in yards or on local traffic, where range between refuelling really isn't an issue.
@@beeble2003 ah makes sense.
Yeah, I've also heard old or broken units are used for "load" test duty as well...
Slugs are perfect for yard service. The single generator provides plenty of amps for 10 mph or less, so suited well to starting whole trains in motion. But not mentioned is that, at least in older designs, the slug will cutout about 10-15mph and then is only good for braking. EJ&E had a few that were unbeatable for used in USS Gary Works moving coke, slab/plate/coil trains around the mill.
Growing up in southern oregon in the 90's, one of my earliest memories was seeing one of southern Pacific's TEBU slugs sandwiched between two GP40s. That was an enormous slug
Damn you weren't joking. That is a big slug.
Thank you for the detailed video essay of SLUGS. I hear and see them, but no one shared any detail about them. After watching this video, I feel a better informed!
Thank you for watching!
From what I understand, a Diesel locomotive at low speed still puts out *a lot* of electricity. So, rather than waste it they put the electricity to use powering an extra set of traction motors in that slug. Thus, you get some extra pulling power without having to fire up another Diesel. It's like an extra locomotive without the extra fuel, pollution, etc.?
@xheralt Seems more like the power of *two* engines with one prime mover - Diesel from the mother + extra traction motors?
@xheralt yes there are limits on what a set like this can do but those limitations lean more towards lack of speed more so than lack of pulling capacity... units like this are designed to pull long heavy cuts of cars in a yard setting but with relatively low horsepower has a low top speed (horsepower is related to speed once the train is moving)... as far as grades go trains need a combo of BOTH HP/tractive effort, lacking one or the other equals stalling
There is only so much horsepower one diesel engine puts out.... plus you need a larger generator to feed more motors
@@JungleYT "Seems more like the power of two engines with one prime mover" No. The power comes from the diesel engine, and you're not adding more engines. Generators and traction motors only convert power from one form to another. The point of slugs is to get more tractive effort which, informally, is basically grip. If you put the same amount of total power through more traction motors, you're putting less power into each individual motor (i.e., each axle), which means the wheels are less likely to slip.
@@beeble2003 So, less power = less slip? That's confusing... Unless you mean like a lower gear in a transmission giving more torque?
I remember when the ECO units were brand new. Hard to believe they've been around for almost 6 years now
We had some 'slugs' here in France in the 90s, used in yards (BB64700), made from shorten units. They were called 'trucks'.
Splitting the power on more wheels reduced slippage, while using more motors reduced their overheating at low speed.
Of course you had slugs in France. You have _escargot_
@@coloradostrong8285 that would be snails, ingenue
@@FaustoTheBoozehound Still slimy.
Are slugs really "becoming more common"? My understanding was that they were actually decreasing in use. NS has scrapped a lot of its ex-SD40 yard slugs; BNSF and KCS have only a handful in service. CSX has a lot of slugs, but they're all conversions from locomotives built in the '60s or early '70s, so I think they were "slugged" quite a while ago.
I agree... great video but I also agree the slugs are disappearing
I think only 7 of the 6-axle slugs have been retired... but regardless, their use is decreasing. Some of that is PSR... close a yard, don't need slugs. Slugs are also niche usage, as they have to have a mother, something that doesn't jive with the 1 loco for any use mantra. I'll always have fond memories of the mid-90s, when NS ran a coal train out of Bluefield down to Knoxville three days a week, with many a GP40/RP-E4D/RP-E4D sets front, mid and rear.
Thanks for a Highly Informative video. There was NO shortage of information included here. Thx!
Thank you!!
I thought that they were called slugs because early versions just had a low, long 'box' as a superstructure and, when coupled to a loco, the loco cab was the slug's head and the extra cabless unit was the slugs tail?
This is the only video on youtube that actually explains what a SLUG Unit is properly. Great job.
Thanks!
As it turns out, I had just been wondering about this. Thanks for a timely and informative video...
Thanks for watching!
Aye, if you haven't heard already, NS 964-08 (Roanoke, VA - Macon, GA) is currently sitting in Greenville, SC yard, track 5. He's been sitting there for about 23 hours without a crew. 964 has SD70ACC 1800 leading 20 ex-ns SD70M-2's (now PRLX) as a funeral train.
Interesting! I'd like to see that!
Wow I am so happy I came across this video. I drive by a local CN yard everyday and have not been able to figure out what the slug engines were used for or even what they were until watching this. Thank you, I love this channel!
I've seen units like this. Illinois central (CN 7601 and 601). I always wondered about all the connections between the two! Thanks for the great video
So the term "Slug" is synonymous with gastropod as it is a slow mover like the gastropod. I could see why they added ballast to weigh it down.
You are a fountain of useful and interesting information. I always learn something when watching your videos. Thank you!
Thanks!
Another interesting video. I continue to learn more about railroading from your channel. Thanks.
Thanks for watching!
Seems like a more modern version of the Class 13s we had in the UK from the mid 60s to the early 80s. These were rebuilt from Class 08s, small 0-6-0 diesels used purely for yard work. One of the pair had it's cab removed and was fitted to be remote controlled from the other. They were used in a hump yard for marshalling heavy trains, since a single large loco wouldn't get over the hump. The big difference is that the 13s kept both engines, but as said removed one cab.
2:03 there’s a heritage unit that’s visible in that shot
ive been to Macon, GA And Atlanta, GA Before. and i have spotted those many times. They are rare in Downtown Augusta GA. But I see them alot.
One of the best explanations of why a RR would use a slug. Thank you for the clarity :)
New subscriber. Enjoy your informative comment's and excellent photography. I've always wondered about "slugs"? Understood somethings but now know much more. Thanks for your channel.
Thanks for watching & subscribing!
Follow-up question. On the slugs that had been rebuilt from regular engines, and that have fuel tanks, are the fuel tanks on the slugs used to fuel the Mother unit via another connection, or are they just empty of filled with ballast of some kind?
I don't believe the NS Slugs are capable of storing fuel. There are slugs out there that can serve as fuel tenders though. I'm not sure if they put the ballast in the fuel tanks.
some roads have put ballast in the fuel tanks (concrete) on slug units... a VERY popular ballasting area as a matter of fact
They also strip the power assemblies and exhaust stacks from the Diesel engines and fill the blocks with concrete and then stack a bunch of 4” thick steel plates at various locations in the engine, air compressor, and main alternator compartments for extra weight.
They mostly don't store fuel in the slugs. It would be a lot of complicated plumbing and fuel capacity isn't a big problem for slugs, as they're almost always used either in yards or on locals.
@@beeble2003
I’ve worked on a road slug set that had a 4 axle slug with a GP-40-2 on each end, the slug was rigged at both ends to carry and supply fuel to the two mother units. But all of the newer 6 axle slugs have the filler adapters removed and the fill pipes are capped so you couldn’t put fuel in if you wanted to. The tanks may even be filled with concrete. I know the engine blocks are and there are also the steel plates I mentioned earlier.
Next step would be to swap out the ballast in the slug, for batteries (recharged by the dynamic braking). Even less fuel would end up being used...
I seen that southern heritage.
What a neat design! A way to reuse old locomotive and to make them more efficent! Take notes people!
I grew up in Conrail (now CSX) Country.
One thing about them (and CSX today): The LOVE their slugs.
Was always a fun pass time playing "spot the slug"
If I had a penny for every video I got recommended about Railroad Slugs.....
I'd have two pennies. But it's still weird it happened twice. Great video by the way.
I saw a slug like #892 pass a crossing near me once. I'd never seen anything like it and for a while I thought my mind was playing tricks on me.
Imagine putting an actual slug next to a railroad slug
CSX been doing this for a lot longer along with Santa Fe and the Burlington Northern when the Railroads were interdependent of each other.
CSX uses the term “road slug” which is basically a locomotive with the prime mover removed and instead of getting their power from the prime mover they get it from an accompanying locomotive.
There are Road Slugs and Yard Slugs. CSX was a big user of Road Slugs. Typically a converted GP30 was the Slug and it was mated to GP40-2. They also used cabless Yard Slugs and still do.
Really interesting never seen these before. I was a train Technician/ commissioning engineer in the UK for many years on our railways (railroads). Thank You
A most excellent presentation. Thanks!
Thanks for watching!
OUTSTANDING cinematography! Exceptional combination of pan, tilt, zoom, closeup. Please tell me what fluid head tripod and video camera you are using here. Thank you!
Thanks! It's an E-Image GH06 tripod with a Sony NX80 camera. Highly recommend both!
Makes me wonder if it would be possible to replace the Diesel Engine with a large Battery in a Slug, to charge it via Dynamic Braking (then called Regenrative Braking; common Practice in AC Electric Trains) and smoothen out Load Changes on the Diesel Engine in the Mother Locomotive. The latter is what Hybrid Ships have Batteries for, as smoother Load Changes reduce Emissions, especially Particulates and NOx.
I love those little suckers and switchers which no 1 uses any more.
Worth noting that those coupled "trucks" - as they're called all over Continental Europe - have been used for ages (probably more than a century) mainly with diesel electric shunters in goods marshalling yards. A very famous example is the French C-61000+TC-61000 double unit of two small 0-6-0 diesel shunters.
Another great video!
Thanks!
I was driving along the Tacoma waterfront that the BNSF - UP shared mainline between Seattle and Portland runs along and saw two new looking NS slugs in black in between the regular locomotives clear up here. I couldn't hardly believe what I was seeing but that's been 20 years ago now. So I'd say yard slugs are more common today then any on mainline duty at least around here. Either way slugs are a rare sight indeed and getting rarer from what I see...
On a side note I have seen what was labeled a State of Washington scale car used in weighing and proving large capacity industrial type scales used in railroad situations that looked at first glance just like a slug only it was a flatcar length car that wasn't as long as a regular slug or locomotive. So I wonder how many have seen that particular railcar and thought it was a slug???
Ding ding! I'm a tram and I approve this video! Great footage!!
Well put together video with useful information.
Thanks!
For things like yard slugs, why don’t railroads bite the bullet and just get overhead electric traction. It would reduce down time, fuel costs, and the potential upfront costs would be minimal compared to mainline or even branch-line electrification due to the confined space and numerous rerouting possibilities that reduce possible capacity issues.
Well work it out! I admit it is a bit complex but it has to to with MONEY.
If it were cheaper to go electric then they'd be going electric. That's free market economics.
About these parts they tore down the overhead on a route, then put it back up and extended it, then took it down again - the last time permanently all within a space of about 10 years.
Now there is some other stuff and that is infrastructure. If there isn't enough supporting infrastructure ie power stations and the ability to supply the route with power, no matter how efficient electric is then you can't build it anyhow. It works in the geographically large Europe because they have many small independent countries many of them with abundant hydro and or coal and nuclear.
Often enough in Europe the rail systems are state owned. In the US much of it private competing companies.
Electric works in the US on those routes where all the criteria is met and those that don't have the criteria met don't have electric. Economics.
Have a look at the Milwaukee Road and its demise. It was all very sad. They had electric on some routes and couldn't make it work but that was a different time - HOWEVER - the market forces acting on that railroad causing its demise gives many lessons on the viability of electrification and distance. Also in fairness Milwaukee Road disappeared for some other reasons to do with treachery, failure to change and modernize, incompetence; all the usual sort of thing. Probably the electric routes were subsidizing the Diesel routes in the end keeping the 'house of cards' standing.
Many of their electric locos were mechanically sound by design, in fact so much so this is why they lasted for so long in service but the market perception in the face of competition starts playing a part on the business model.
What I haven't told you is a lot of the overhead on the Milwaukee Road was supported with wooden poles in likelihood cut directly from the forest it passed through.
Well you're probably not going to get away with that these days.
th-cam.com/video/71BwMlRR0pc/w-d-xo.html
🤔Strange i've been buying engines without motors some in ATHEARN, an old Tyco FB unit. I took out & demotorized a GE U 23 by BACHMANN it had a gear that kept slipping out of the drive shaft. Now i'm watching this & i want to model these in NORFOLK SOUTHERN! 😃😅😅I Enjoyed watching this!
2:06 we just gonna talk about the southern heritage unit right there
Great video 🚄🚄👍
Cow and a calf is the term often used also.
A Cow and Calf would be a Conventional switcher (with a cab) and a B unit. Not a Slug and a Mother.
I've heard this term lately and didn't know what it was. Thanks for the education!
What ever happened to the old Conrail MT slugs they made from old Alcos? Looks like they're all gone from the NS roster, did they find homes or just scrapped?
Slugs are a pretty genius idea
The green and black livery looks really nice.
I thought they were called slugs because they are flat and long like slugs
Excellent presentation. Thank you.
Road slug denotes the fact it has a cab and can be operated by the engineer just like one with an engine. Engineers liked the slugs on the road because they were a lot quieter, but were 'outlawed' due to the fact they could not sound the bell on the mother. Sounds like a weak excuse to me. How hard would it be to put an electronic bell on the slug?
Probably not hard at all
Not sure who told you they were outlawed because of the inability to operate the bell on the mother. That’s completely incorrect. And for obvious reasons. You can’t activate the bell or the horn on a trailing unit in any consist. Makes no difference if the other Locomotive is a slug or not. And there is no requirement to able to. All that matters is the horn and bell operate on the controlling locomotive.
@@FFred-us9tw The point was that the slug did not have a bell and could not legally lead a consist. At least that was UPs excuse.
Excellent video. Expert photography. Thank you!
Thanks for watching!
i live in Atlanta and from the air as a HEMS Pilot, i have seen 653 and noted the lack of exhaust and fans, i was like, What the heck kind of loco is that?
I spotted the other slug down in macon once doing a long haul NET Patient transport that one got a much more prominent response ( a WTF )
Thank you for posting this video, now i know what 653 is and one of my air nurses is a big train guy, ill share this video with him.
2:04 I don’t think he saw the southern heritage unit
I Like how the engine is called 4723 Nice reference NS!
‘9
Union Pacific
The railroad where I worked bought a rebuilt GP-50. 3,000 HP on 4 axles. Despite electronic wheel slip control, it was very susceptible to wheel slipping especially starting on a hill or during lease season. Even with sand, it was very loose. Too much HP, not enough weight and wheels on the iron. Anything over 1,800 HP on a 4 axle locomotive really doesn’t help. I’d rather have two locomotives.
Railroad Slugs have always been kinda terrifying to me. They're like a human without a face
Did anyone else notice the Southern Railway painted locomotive at 2:02?
Heritage unit
awesome
makes one wonder if the next phase is to fit the yards with AC overhead catenary and just run fully electric switchers. Or DC third rails. I have heard overhead wires require a lot of upkeep though. Only reason I thought of them before third rails is for RR workers in a yard you wont ever have someone accidentally step on an overhead wire.
An electrified third rail would be insanely dangerous in a yard. Workers need to connect brake lines and so on.
This gives me an idea for a remote-controlled diesel locomotive. The idea would be to take an old slug, put an array of batteries in it, and put some remote-controlling equipment in it.
Ngl That green on those NS locos looks sick
I wonder if CSX Burlington Northern Santa Fe have them too in Canada you are looking at Canadian Pacific Canadian national having these slugs. Across the Atlantic Ocean the French SNCF uses them too.
Awesome video!
Thanks!
Thanks for the video, I have a much better understanding of railroad slugs now. There's a railroad that runs through my city called the St. Lawrence and Atlantic really railroad and they have a road slug.
One advantage of operating the train from the slugs, is a very quiet operation. No engine noise to deal with.
Grean engines make green plants grow
Both slugs would look great on a layout! And of the ‘makers’ seeing this?
cool video , learn something new everyday
Interesting Video. So would that weight of the slug be nearly equal to an ordinary comparable unit?
i saw one of those green Norfolk Southern engines at a chicago yard.
I live I Macon and see these slugs all the time! They're cool, and I like the color scheme
Interesting. A slug allows a single locomotive to use all of its output capability during the few times it is actually required. Unfortunately, the length of a train and the numerous couplings needed prevents them doing this instead of using separate engines for distributed power requirements.
Slugs don’t make any sense on high tonage road trains operating at higher speeds. The extra power they require from the mother Locomotive is only useful at lower speeds. Even most road slugs like some railroads used such as CSX would cut out typically around 30 MPH where all the horsepower the mother locomotive was producing was needed for those traction motors. At that point slugs are just dead weight. Which is why they aren’t even considered an option.
I saw a slug on a NS train I couldn't tell what kinda locomotive it was converted from
Nice video! Thank you.
Thank You- I definitely learned something new and interesting in this video.
Thats a "tractive effort booster" or "booster" their just traction motors that take electricity from another locomotive. A slug is like a booster but they have diesel engines with no crew cab
No, you are confused. This video shows slugs. A slug has traction motors but no diesel engine. A slug can have a cab, we used them on CSX for years with old GP30's with the diesel removed and they were mated to a GP40-2. Most railroads have slugs with no cabs. But a slug will NEVER have a diesel engine.
A locomotive with a diesel engine but no cab is called a "B unit". Often referred to unofficially as a "Booster" but they were never called that by the builders or by the railroads on their rosters. They were simply a B unit. Locomotive with no diesel engine but may or may not have a cab? = SLUG. Locomotive with a diesel engine but NEVER a cab = B Unit.
Does anyone know why Subtitles are not available on most TH-cam video's?
What you have is a UP DD40X running with one motor. Makes you want to put a lawn mower motor in your car.
Can a DD40X power all 8 traction motors if only one engine is running?
No, as a DDA40X cannot operate all 8 motors from one prime mover.
@@atomstarfireproductions8695 no. Each prime mover powers one truck only.
Very cool, I have never seen a loco like it
Thanks!
Nice man
Thanks!
thank share detail video
interesting idea, I can imagine the idea being adapted in Australia. Be a shame to see an S class slugged to a T class. May as well leave the engine in it rather than replace it with concrete (or fill it with Li batteries).
The engine is valuable, either to use as an engine or to sell for scrap. If you left it in the slug, it would be a very expensive form of weight compared to concrete or steel slab.
Slugs just seem like modern tenders
What is the benefit to removing the engine? Is it used for spares on other locomotives? It seems if they are going to fill it with concrete for ballast anyway, they might as well keep the engine weight in the locomotive and save themselves a bunch of work.
The engine is removed because it isn't needed. At lower speeds, such as in yards most locomotives produce more power than that can actually use. As an example, the EMD GP40-2 and SD40-2 use the same engine and HP output. The SD40-2 has two more axles though that utilize this extra power. Well that surplus power is more abundant the slower you go. So by using a slug you can end up with the pulling and braking power of two locomotives with the engine maintenance and fuel consumption of one. Once you start going fast though this does not work as well and the power is lost. So most slugs are for yard use although some railroads like CSX had Road slugs which would produce tractive effort till around 30 MPH.
@@FFred-us9tw Oh no, I don't mean use the engine. I assume the locomotives that are being turned into slugs are probably older anyways. I'm saying why remove the engine and then add in extra ballast? Engines are heavy. Why not just keep it there as weight, and then you would still add ballast, but you wouldn't have to add as much.
@@v12tommy the engines are reused on other locomotives. Way too expensive to basically abandon in a locomotive. They can be infinitely rebuilt.
@@FFred-us9tw Oh, gotcha. I figured they were older and no longer met emissions requirements, or weren't efficient enough to be profitable or something.
Slug is better than that new pod train for carrying container
My question is, why do the locomotives still used incandescent lighting for the headlights instead of LED bulbs? Ever seen the headlights on newer firetrucks?
Many reasons. More than anything, cost. A standard 350 Watt PAR 56 locomotive headlight cost around $18. An FRA approved LED version (Presently only 3 brands make them) cost around $800. The biggest selling point LED bulb manufacturers push is the fact they last longer. Which is true. But considering it takes about 5 minutes to change a bulb on a loco the labor cost's are hardly an issue. And to make your money back on longevity almost isn't worth the initial cost.
Incandescent bulbs put out a much warmer light that penetrates fog and snow better and will never ice up because of the heat they generate. LED versions have to have heated lenses to melt snow and the heaters don't even work that well in heavy snow. We run LED headlights in all our new Loco's and while they are bright, i much prefer the incandescent bulbs for bad weather and they are easier on your eyes.
@@FFred-us9tw Thank you. First answer I have received to my question and it make sense. Like the traffic lights that changed over to LED's but they get the snow buildup. $800 for an LED? Sheesh they were cheaper when they first came out.
@@coloradostrong8285 They are built very heavy duty. Heavy aluminum housing with heat sinks. Weatherproof connectors. Thick outer heated lens and multiple lenses to focus the light. No real way to make them cheap I guess.
@@FFred-us9tw Thank you again. Any sites to peruse over the products, as I need some lites for my riding mower. 😅
@@coloradostrong8285 check out Railhead Corp. and J.W. Speaker corp.
So essentially, a slug along with its mother unit is technically, a DMU
Couldn't NS go and replace the engine they left 30feet outside my dorm room for two years in college with one of these quiet ones?
I never seen a Norfolk southern train look like this
I only seen them used in rail yards
Something like the previous B-Unit locomotives.
A B unit has its own engine. Slugs never do. Two totally different types of equipment.
Actually in modern times you would only need to transfer the power and 2 data cables, maybe a pneumatic added, but that technology connecting them with countless cables is probably like 50 years old. And since the manufacterer can justify the costs when its countless connections they stay with that. Is there a legitimate reason for having that many cables?
It's not "countless cables" It's ONE control cable. ONE. The larger cables you see are high voltage cables that power each traction motor. They are not "control" cables. The cables have to be that large to carry the amperage. You can't make them any smaller. And you can't make any less of them. And the air hoses are standard as well. Brake pipe and 3 MU hoses.
The standard 27 pin loco MU cable has been around forever for good reason. Because it's very heavy duty, extremely reliable and pretty much every locomotive in use today (even ones built 60 years ago) have the connector for this cable. Meaning a 60 year old loco will MU seamlessly with a locomotive built yesterday. Changing the design now would be beyond stupid because you would make every older version incompatible. Railroad applications are like nothing else. Things have to be built very heavy duty. Modern data cables and fiber optics would not last in an MU application and god knows we don't need or want any more wireless nonsense.
@@FFred-us9tw Well these are a lot of intresting details that definetly would be good in the video.. maybe i missed them somewhere, but then i was only 10 years off with guessing that the system is 50 years old it seems.
I always thought they were called "slugs" because they kinda looked like slugs.
Ns 892 is the wierdes engine I’ve even seen just now
I dont see how they are making anymore money as they would still need more locos in front and as a dpu ... seems like allot of shell just for traction rather that pull/push power. Plus you need a larger generator on your main power loco.
Spreading the mother's fixed amount of power between the mother and slug's traction motors means less power per axle, which means less wheel slip. Basically, a four-axle unit can't put down all its power at low speed because it doesn't grip the rails enough and the wheels will slip. The slug allows the mother to use all its power at low speed, which is useful for switching.