QUOTE A 1967 Triang Hornby Hymec with Magnadhesion on steel track could pull 11 coaches according to press reviews of that year. On nickel silver track it struggles to pull 5 coaches! It can only pull 2 Hornby Dublo tinplate coaches on nickel silver track.
A Hornby Dublo diecast loco can easily pull 6 tinplate coaches without magnadhesion
It seems that locomotives now
have to be heavy to pull any weight.
Note that the Dublo is alleged to have three times the pull
The word "now" should be omitted.
They just need to be heavy, whether then, now or in the future. Dublo locos were
and it's that simple.
Weight is the first and most important key to good running and haulage power.
As we are frequently reminded, British steam locos are nothing like as intricate as those from most of the rest of the world, so there is very little reason why British models should not utilise metal bodies at a reasonable price. Other than the urge to leave space for digital electronics, there is also no reason why cavities can't be filled with weight by the manufacturer. This is done very effectively in non-Brit N gauge and N gauge locos are PRODIGIOUS haulers! I can't speak for British N as I have none for comparison.
While magnetraction solved a problem, it was an abomination - a sledge hammer to crack a nut. It created problems of its own, with serious friction effects that put a massive strain on motors and rendered low speed running virtually impossible. That's the real reason why it is dead and buried, not nickel silver rails! Is Hornby track nickel silver these days?
Further necessities are low friction axles and wheels on all rolling stock AND good maintenance of these. An awful lot of people allow the most appalling crud to build up both on wheel treads and, less obviously, in the axle bushings. Gunged bushings are a lethal haulage crippler and though cleaning and lubing these is not the manufacturers' responsibility, providing precision axles, bushings and rolling stock wheels in the first place is. Wheels must also be concentric and axles must be straight.
As for enhancing electrical pickup - traction tyres don't help in this, but precision designed and manufactured wheels and SUITABLE tyres are actually not that much of a detriment. Unfortunately the precision manufacture requirements and suitable tyre materials are not always provided! In those cases, the tyres are a menace. I have to assume most people prefer their absence or we would see more of them present. Another recommendation for good pick up is to provide it on ALL wheels, not just the drivers. This can and does provide a very significant improvement.
I'd just add that electrical pick up is an area where 3-rail can really score, particularly where a long skid is used in the centre. The sliding action helps to keep contamination of any sort at bay and the number of pick up wheels is automatically doubled for the other polarity - a definite high score for 3-rail! (studs preferred)
A further important factor, particularly for steamers, is precision design and manufacture of the entire chassis. If just one wheel is even slightly out of alignment or not perfectly round, then both electrical pick up AND adhesion are drastically impaired. It is in this area, perhaps most of all, that the more expensive products score more highly - and also the commercial exhibitors. It stands to reason that no one but an idiot would pull a brand new loco straight out of its box and run it on exhibition without careful checking, extensive test running and, adjusting as needed, even totally replacing duff candidates! This is the MAIN reason why one rarely sees derailments at exhibitions. It's a product of the six Ps rule.
"Perfect Preparation Prevents Piss Poor Performance"!
(and woe betide anyone who ignores it!)
Your average kiddy at home usuaully does not appreciate the huge importance of this and it's simply not realistic to cite good exhibition running as some form of 'evidence' that cheap RTR locos are as good as more expensive, precision jobbies. - they aren't.
There's more but I'll just fleetingly mention that if the 'average OO Brit at home' has only an 8' x 4' oval or less, then it's doubtful he will ever haul more than 4 coaches and, if he did, he would immediately run into massive friction problems from the viciously small radius curves. Would more than 4 coaches plus a loco ever get an unrestricted straight run in such a layout? So maybe certain manufacturers reckon that their locos don't need the ability to haul any more than they do . . .