Speed vs. Volume

[Baldy's Boss]

The Gren-Gren Express is getting due for an overhaul...but its bilevel trains,capped at 100 mph,are top earners,and going maglev means it can't have bilevel trains any more.(The nearby Netown-Brutfield run also gets more money out of its bilevel trains than out of its fast train).So should I just run engines that get heavy trains to 100mph quickly,or should I convert the whole group and its tracks and stations to maglev?
Ratings took off when Buborough-to-Penbourne and Great Loop went maglev,but I do care about RoI.
Some of the older engines are dying,so I can't do nothing,and a parallel route would be awkward.

[Baldy's Boss]

In the years since I ran the B&P,I've added other NewGRF vehicles that have expanded the speed vs. volume debate markedly.It has seemed fairly settled that the high-capacity freight vehicles earn more money than is possible with the capacity-limited maglev wagons despite the much higher speed of the latter,so my more recent games such as Tradingbury Mountain have foregone my previously typical full-court press toward a maglev network by 2051.

And yet I'm running into profitability problems on certain services of the Liverbridge Jintyrail Group despite high volume,such as Sundnor-Charnwell Coal.
Is this a matter of reliability issues?
Track geometry?
Signals?
Running costs of the chosen vehicles?
The route being too short?

Advice is welcome...I will maglev-ize where that would be the only way to enter profit but want to stick with the high-volume traffic where that's indicated.

[Baldy's Boss]

My previous queries on the topic here have generated plenty of downloads but no advice on how to manage the tradeoff but perhaps the third time will be the charm.
My ever-broader menus of NewGRF vehicles have generally had me sticking with volume rather than going with the speed increase I've only had available with maglevs...but the mountainous terrain I have to overcome has been an adverse factor.
In the attached save I had contemplated posting asking where one should choose a site for a funded industry but I finally located a factory that could take the steel that was getting produced...but my heavy trainloads of steel are taking a long time to deliver and the loaded steel trains (59 & 60) are holding up the ore trains on the shared sections of track.I am not sure if profit is possible and what changes would enhance performance.Please...input!

[peter1138]

Probably the steep climb out of Windburg Bay Mines doesn't help. P.S. You should probably post screenshots if you want more feedback

[Alberth]

The Bendy Construction Company has looked into your challenge and proposes to add a few bends to the climb:

Screenshot_20190416_192730.png

(1.5 MiB) Not downloaded yet

They also note that the station might better served, and trains could be improved as their reliability isn't very great. Steam or Diesel engines might be useful here.

[eekee]

Vactrain Set 1.01 has powerful multi-deck trains. There's a parameter to run them on maglev tracks too, for which each train has an "atmospheric speed", most in the range 200-640 km/h. Its worst point is you have to build a train to see its true capacity and running cost, but I guess that's true of many GRFs now.