Co-Co & Bo-Bo

This sounds like 2 names for performing poodles in the circus. After reading the thread about railroad reading, I ordered several books (again). One talks about diesel locomotives,describing them in the European type system/ Co-Co, instead saying “C” trucks. Can someone explain their system of calling wheels to me?It kind of makes me think of any book about European history, that uses a lot of french phrases without any explanation.

Check out “The Great Book of Trains” by Brian Hollingsworth and Arthur Cook (Salamander Books, 1998). Page 215 has an explanation of this.

Bo-Bo indicates two 2-axle trucks, with each axle separately driven. If the axles in each truck were connected with rods, it would be designated B-B. If only one truck were powered, it would be Bo-B.

I’ve lived here 20 years and work in the industry and still can’t work it out… Luckily it’s something I don’t ever have to talk about.

What about the ubiquitous 08 shunter? http://www.railwayscene.co.uk/image.php?imgref=506 3 axles, connected by rods, but only 2 traction motors. It would be an A1A in my book.
Have a look at http://www.railway-technical.com/whlarr.html

Then what are the three axle trucks I have seen pics of with little pony wheels added to spread the weight out over 8 wheels called?

Adrianspeeder

The same designation is ised on the USA refering to electrics. A GG1 is technically a 4-c-c-4. The little 0 after the letter indicates no pony or guide wheels,

In the European system, groups of powered axles are indicated by letters (A = 1 axle, B = 2 etc), unpowered axles by numbers. The lowercase “o” after a letter indicates the axles in a group are individually powered, rather than mechanically coupled together.

So a locomotive with two 4 axle trucks, with 3 axles grouped together and individually powered on each truck would be: 1Co-Co1 (assuming unpowered axles at the outer ends)

The same thing but with the powered axles mechanically coupled would be: 1C-C1 (French railways used to be keen on ‘mono-motor’ trucks so they have a lot of B-B and C-C electric locos).

If the two trucks were articulated i.e. coupled directly together as well as via the locomotive body, then it would be : 1Co+Co1 or 1C+C1

A loco with two 4 axle trucks with alternate axles powered would be: 1A1A-A1A1 (although I’ve never come across one!)

So under the European system, a GP40 would be designated a Bo-Bo, an SD40 a Co-Co

Tony (from the UK)

Adrianspeeder:
You’re probably thinking of the U20C1’s in South Africa and Namibia. According to my records, they’re shown as 1-C-C-1 in AAR style notation.

So, would the A1A truck under an E unit be called out as Ao-1-Ao in the European system? And just for fun, how would they call out a Baldwin Cetipede?!?

You don’t need to put the o after an A.

My guess for the Centipede wold be (Bo)Do’Do’(Bo)+(Bo)Do’Do’(Bo)

Why do you put the o after the C (Co-Co), but not after the A in (?)A-1-A? Your centipede call out sounds like the beginning of “Here Comes the Bride”.

Well the o just indicates that the powered axle is not couple to another powered axle, A is a single axle so therefore not coupled. It is only if you have 2 or more powered axles you need to state weather they are coupled or not.

The big Union Pacific DD35 and DD40x units were a Do’Do’
sounds like an extinct bird.

YOu don’t need an o behind an A becuse A truck is by default individually driven ^^

Centipede would be

2Do’Do’2 + 2Do’Do’2

GG1 - 2Co’+Co’2

DDA40x - Do’Do’

SD40 - Co’Co’

Good explanations.

Each unit of the Centipede would be 2Do-Do2 (I don’t think the two units being coupled together makes a difference, they are treated as two separate locomotives).

A Pennsy GG1 electric would be 2Co+Co2 (the ‘+’ indicates the two trucks are articulated together).

Tony

Didn’t the minus / plus sign between the bogie symbol indicate whether Diesel Locomotives were powered by two separate Engines (and separate Generators / Torque Converters) or one single bit of Kit?

Not as far as I know. Don’t forget that what we’re discussing here is a scheme for describing wheel arrangements - other than the use of the ‘o’, it doesn’t say anything about power sources. I think it grew out of a similar scheme used by the German railways for steam locomotives - see http://www.railway-technical.com/st-clasif.html

This page - http://www.railway-technical.com/whlarr.html - also explains that in some countries they use an apostrophe (') instead of a hyphen (-) as a separation character.

Tony

Thanks for sharing the info. Uzurpator according to your profile, you live in Poland. What are some of the things about American railroading that seem odd to you?

This might be a good place for it: lets see what all the differences are between North American and Briti***erminology for railroads. Here’s my go:
1.) Diesel wheel classifications
2.) Trucks/Bougies
3.) Fireman/Stoker
4.) Engineer/Driver
5.) Conductor/Guard
[What do you call a brakeman in England?]
6.) Truck/Bogie
7.) Cowcatcher/Pilot (though we use pilot out here a lot)
8.) Siding/Passing loop
9.) Wye/Turning triangle
Do you say “turnout” or “switch” comonly in Britain (here “turnout” is technically correct, but everyone says “switch”)?

Sincerely,
Daniel Parks

2.) Trucks/Bogies
3.) Fireman/Fireman

5.) Conductor/Guard - usually, but we also use ‘conductor’, more commonly on passenger trains.
[What do you call a brakeman in England?] - we don’t have them. Standard crew on a steam goods (= freight) train was driver and fireman on the engine, and a guard in the guard’s van (= caboose) at the rear. Nowadays, most freight trains running on main lines only have a driver, and if a guard is carried they ride in the rear cab of the locomotive.

7.) Cowcatcher/Pilot (though we use pilot out here a lot) - pilot is the correct term, but since all railway lines in the UK have to be fenced by law (since Victorian times) we don’t have the same need for cowcatchers…

8.) Siding/Passing loop - correct, but we use ‘siding’ to refer to dead-end tracks - a ‘spur’ in US I think.

Do you say “turnout” or “switch” comonly in Britain (here “turnout” is technically correct, but everyone says “switch”)? - we use both ‘switch’ and ‘points’.

Also,

10.) Freight car/wagon
11.) Switching/shunting (so a switch engine is a shunter, as is the person on the ground coupling and uncoupling wagons.)
12.) Interlocking tower/signalbox (and the person operating it is a signalman/signalwoman)
13.) Passenger car/coach (but sometimes carriage or car)

Tony

Oops, my “guess” for the Centipede was because I thought without looking into it that the front and rear trucks were powered. But I then do beleive one of the big Great Northern electrics would have had this arrangement but as a single unit, not 2 units permenently coupled.

  1. tie / sleeper