Morning all, I’ve been in the workshop for the last 2 days, but I’m designing the NLW MP350-T4 Prime mover, and I have a fully functional 1:36 model of the MP350-T4 and its a steam variant not actual diesel and its made of copper not steel or metal, but I designed a B-Unit version of the MP55CACW-T4 Called the MP55CACW-T4B but even if I did get the production unit started for the NLW will a railroad buy the B-Units?
anything helps!
By the way, Teagan Says Hi, and she hopes everyone has an amazing Cinco de Mayo!
In a sense, Iden’s ‘tender’ for his version of dual-mode-lite acts as a B-unit in making up consists. If ‘obligate’ use of hybrid or dual-mode-lite with add-on modules succeeds as a marketing and business model, then providing the “operating assistance” as cabless modules to be wired to ‘mother’ units would make sense.
I would argue that there’s better value in having a ‘cab’ on every unit in a ‘hybrid’ consist (essentially treating the battery/road-slug as a locomotive like a FLXdrive) so that any combination of battery and power can be easily ‘driven from the front’ and rearranged with the normal kinds of power change.
I doubt the idea of MATEs would make much of a comeback, particularly if hydrogen-carrier or ammonia fuel for the ‘alternatively-fueled’ units in a consist are built.
That’s a very good/valid point, @Woke_Hoagland, but again, it’s a 6-Axle big road diesel that’s capable of producing almost 6,000HP, it’s supposed to be semi-permanently coupled to an ‘A-Unit’ MP55CACW-T4 but I’m also considering a dual engined MP series locomotive with 2 20-MP350C3A-T4 prime movers
The age of double-engined high-horsepower diesels came and went with the DD35 and the early DD45s. Note how quickly UP slapped cabs on the Centennials.
In that era, ordinary power consists could run north of 17 Geeps, so it’s not surprising that the UP would consider high-horsepower units combined with geared-up SD40s. But we no longer live in any sort of world that values speed, which was the purpose of high horsepower per unit; the utter failure of 6000hp locomotives to thrive in domestic service is not all related to cavitation or mismatched combination power.
A 6000hp obligate B-unit implies a ‘cabs-out’ consist of 18,000hp, which is better interpreted in terms of fuel burn at notch 5 restriction for a corresponding train resistance.
The salability of offering these as if they were big genset engines – e.g. that you have 12000 to 18000hp from 4 or 6 engines, but can shut off power all the way down to 3000hp (and run on hybrid battery assist where installed, keeping all the AC traction motors powered if desired) is as attractive in theory as it was for the Essl locomotive. That has not proven to be valued in modern use, but to a significant extent that’s because it has been implemented wrong.
In the real world of 1:1 railroading - if it doesn’t have a cab, it is a strike against the units utility. I’ll also go so far as to postulate that carriers could get even more utility were units built with operating cabs on both ends of the locomotive.
With the end of steam, railroads removed most of the locomotive turning facilities across their properties - Wyes, turntables and balloon tracks. With the rise of the 4K+ AC traction locomotives across all the class 1’s there are many trains that can easily be handled to a destination with a single engine, however, when it gets to that destination it can not be turned and will need another locomotive with cab on the other end to get a train out of town back to the original origin.
Power managers desire for efficiency have them tailoring power assigned to tonnage being handled.
[quote=“Woke_Hoagland, post:4, topic:413004”]
Essl locomotive
[/quote]. WHAT? Oh. INNT … that way to describe Diesel Electric. In reasearch I found this which seems good to pass along:
I year ago posted by beartheminus
…good answers here but I think people are missing a key reason that isn’t being explained exactly: combustion engines have a very narrow band of RPM’s where there is peak efficiency. Meaning, only from about 2000-4000rpm is your engine working at its peak efficiency, everything below and above wastes fuel for the amount of horsepower. Its even more narrow for the large diesel engines on trains.
Since locomotives are very heavy, much heavier than cars, you would need an insanely large mechanical transmission to make sure the huge engine is always operating at peak efficiency. Last I recall it would need like 32 gear ratios, be as massive as the locomotive itself and weigh 10 tons.
Electric motors however, work at peak efficiency almost across their entire RPM range.
So its much lighter, easier, and more efficient to hook the diesel engine up to a generator, and have it operate at its exact RPM for peak efficiency and convert that into electrical energy to power electric motors, which work very efficiently no matter how fast they are turning. endmrw0505251340
The ‘modern’ B-units were four-axle, with the GP60Bs being the ‘latest’ EMDs. It is possible that the stated reason for abandonment of four-axle (as opposed to four-motor) units – increased weight and S.580 cab-heavy weight distribution – could be overcome with a cabless unit, but it could only be used with a lighter cab unit, perhaps a dedicated road slug, or in MU with six-axle unit(s) destroying most of the remaining points for using four-axle high-horsepower units.
The epic BNSF consists of B30-7s (some A-B-B-B-B-B-A!) are the result of specific weight an curve restrictions on a particular line. As they run as dedicated or semi dedicated consists there is no need for all units to have cabs, but it remains to be seen if new or replacement motive power retains extensive use of separable boosters.
Im still confused on why B-Units cant be used in other services or like a B-Unit Siemens SC-44 ‘Charger’ or ALC-42 ‘Charger’ for Amtrak since they use more than one per consist
See Balt’s notes about flexibility. The only real purpose of a passenger B-unit is to look more streamlined in a consist; there is no real cost-benefit in making a DL500-style ‘boxcab’ instead of the Vergara-shudder nose, or replicating the AB6 for connecting services.
Some of the operating argument about ‘hostling controls’ (there is a good video about this for the GP60Bs on YouTube) might be amenable to solution with a RCO-like ‘console’ that could control normal operation of a B-unit in emergencies if most conventional operating equipment and computers is provided. Look for that not to be favored from either a safety or crew-convenience standpoint, though… especially on Amtrak.