What Happened to B-UNITS?

The Booster, or B-unit, was once a staple of most diesel-powered American trains throughout the mid-20th century. They were cheaper cabless variants of their A-unit counterparts, and meant to supply extra horsepower. Steam locomotives were still more powerful than the diesel, but the diesel was far cheaper and more flexible. But what happened to the boosters? Why don't we see them on freight and passenger trains anymore?

Music:
OMORI - I Think My Dad Shops Here
Deltarune - Dialtone
Super Mario RPG - And My Name's Booster
OMORI - Finding Shapes in the Clouds
Deltarune - My Funky Town
Deltarune - Green Room
Deltarune - Girl Next Door
Deltarune - Game Main Theme (Piano Sketch)

Links:

[AmtrakGuy]

At 0:56, the 1600 hp should be 1800 hp. Sorry about that!

[YourLocalHistorian]

The AT&SF also converted locomotives that were involved in catastrophic wrecks, destroying the cabs into B units

[hungrymoose]

FUN FACT. Canadian National and Canadian Pacific's E and F B units had primitive control stands in them so they could be shunted under their own power.

[richardjayroe]

B units are used on Donner pass with rotary snow plows

[davidmolin]

I cannot believe that Spamton G Spamton was the salesman’s for the B unit on all the big locomotive builders, bro must’ve really been raking in that cash

[jeesmith]

My dad was a conductor/brakeman for Santa Fe. In his tenure, he called them slugs. He was too late to the a unit and b unit world. He didn’t like them. Especially when the head end was bad order and the slug wasn’t a replacement leading the consist.

[SteamFan]

4:20 Supposedly ATSF wanted a B40-8B to go with their B40-8Ws, but it would’ve costed the same as a B40-8W so they didn’t.

[KCDashcw]

I would do anything to get a GEVO B Unit

[pavelsovicka]

Just as an interesting sidenote: In eastern Europe, especially russia, the term "booster" means a frame with only traction motors and balast (no cab but also no engine). This booster is connected to the main locomotive by power cables in series with its own motors. This basically doubles adhesion and given there are twice as many motors in series it means that the entire unit has double the tractive effort with half the speed. They are only used as shunters.

[vettebecker]

My favorite diesel locomotive has always been the EMD F and E units, we currently own a 7.5 gauge A&B Southern set for our outdoor railroad.

[motorola]

Surprised you didn't Segway into talking about slugs. How the problem went from needing more horsepower to needing more traction.

[rottenroads]

0:08, POV: Mattel Destroying Thomas & Friends.

[DTD]

There was a book I have which I can no longer find, which showed a 1965 color photograph of an A-B-B-B-A unit (or something like that) in Albuquerque which the author claimed will never be seen again. I really wish I could find out where I stashed that book.

[JJRol.]

I really love these videos. They sort of remind me of bedtime stories I heard when I was a kid, always about trains. These videos are super relaxing, especially the ones talking about older history!

[tolucaheights]

The ATSF theme song lives rent free in my head

[OfficialSEICK]

B units are pretty iconic. I usually think of the F and E units when I see B units. Railroads definitely got creative with B units from the streamliners. Classic B units

[jst]

0:01 the streamlined FEC paint scheme was perfection

[MarioYoshi]

I’ve always asked myself this. I once found fanart of an ALC-42 B-Unit and I thought it looked pretty nice.
I sent it to a train meme page and got a resounding: “Absolutely the **** not”.

[douglasskaalrud]

I don’t have any Soo Line F7A units on my layout but I do have two F7Bs. In the Soo Line tight-fisted power scheme of things in the early 1970’s it was common to pair up SD40’s and Dash-2s with an F7A or even an F7B for better unit utilization. That practice stopped only when the Soo started taking delivery of the GP38-2s and they finally had enough power to run their trains in a more conventional fashion. The ends of an F7B are a modelers paradise that are always overlooked. There are no pilot plates so all the plumbing is open. MU and steam lines, cut bars, sand hoses can all be modeled. The control stand in an F7B is for “local control” so a hostler can move them around the servicing area to make up a consist-nothing more. A relative of mine said he’d rather grab a switcher to shuffle units than to actually use the hostler controls . I remember him saying they were not designed for use by humans. It must have been interesting to be a brakeman on the ground and watch a seemingly unmanned brick rolling around.

[RMSTitanicWSL]

Many B-units had hostler controls, and could move independently of A-units, at least at low speed. The Rock Island's two AB-6s were actually considered motor cars by EMC, hence the lack of an "E" designation. The same applied to the AA-6 built for Missouri Pacific, which was similar to the AB-6s, except for having a streamlined front end like normal E6As. Numerous railroads converted road switchers into B-units over the years. Sometimes, the cab would remain, but the interiors (seats, controls, and other cab accommodations) would be removed. This happened with a number of D&RGW GP30s and GP35s, a BN GP38, the CSXT BQ23-7s, and a bunch of UP SD40-2s. As for units that lost their cabs (usually to wreck damage), the list includes a Missouri Pacific U30C (temporary, while waiting to get an EMD cab applied), several AT&SF SD45s and SD45-2s, an SSW B36-7, and a miscellaneous bunch of BN units, including several GPs of various models and a couple SD40-2s. If memory serves, BN was unusual for having a GP38B with its cab structure intact, as well as a GP38-2 with the cab actually removed.