What Gradient ?

In message , RT writes

In the absence of any other information, I suggest 0%.

Try

for a discussion on max gradient.

I have got away with more for an 8' * 4' twin oval sort of thing with the inner oval elevated and the rear gradient just joining the two at the back. Not a lot of requirement for coaches to go up top on that, of course.

Looks as unrealistic as, well, an engine without steam thumping out of the funnel and cylinders though.

"RT" wrote

That's a real 'how long is a piece of string' question, because it very much depends up what sort of train you want to drag up it and with what type of loco.

The real railway regard a 2% gardient (1 in 50) as incredibly steep, and whilst you may get away with something slightly steeper than that, it will very much depend upon the previously mentioned factors.

Personally I'd avoid any sort of steep gradient like the plague, but others use them happily. Don't even contemplate anything less than 1 in 30 unless you want all sorts of problems.

John.

Only in the UK. In Switzerland, gradients steeper than 5% (1 in20) are not that uncommon on some adhesion-worked lines.

At least until 1994, a gradient of 8% (1 in 12.5) pertained for a short distance just outside Montreux station on the adhesion-worked metre gauge Montreux Oberland Bahn (MOB).

In the UK, gradients of greater than 3% (1 in 33) exist, or used to exist on the Folkestone Harbour branch (1 in 26), the line in tunnel from Olive Mount cutting to Liverpool Central (now Merseyrail, 1 in 27 IIRC) and on the Thameslink line in London at City Thameslink (intended to be 1 in 29 but apparently built rather steeper).

"Tony Polson" wrote

There's also a very short steep incline on the East Lancs Railway's Heywood extension, but only because it was totally unavoidable.

As a general rule railway traditionally avoided gradients because they slowed (or even stopped) trains during the steam era, but modern traction isn't quite so restrictive and you'll find that there are some fairly stiff gradients on the newly built French TGV network.

But the OP was about UK model railways, and my original response is still valid.

John.

With respect, John, I was replying to your statement "The real railway regard a 2% gradient (1 in 50) as incredibly steep". The part of your response to which I replied does not refer to model railways.

Anything up to about 1 in 30 will work, but the less steep the better. When calculating the length of the grade, allow at least two feet for the transitions from level to gradient at each end (ie, four feet min. in total.)

HTH

If you wish to haul trains of 5+ carriages then you will need to allow

3M run for 70mm rise. If there are curves involved try to keep them down to 1M radius (or reduce the gradient) It helps to use steel rail if your locos have metal wheels as the nickle type have a lower friction coeff. Equally you must provide ample transition space for start and finish. I have two climbs at 1:35, one straight and the other curved and there is a big difference in performance for any given loco. I am still surprised that the Hornby Cl 52 & 37 are the best followed by the assortment of 47's. On a good day the tender driven 4F can be very prototypical too. The locos of course do need at least double the supplied ballast to be sure of adhesion. When using three consecutive lengths of steel rail I have noticed poor power takeoff. This usually proves to be caused by poor rail joiners (new or otherwise) but occasionally it is the rail itself which has high resistance. This is not uncommon and I have encountered this in ship's hulls where an AVO could not find a circuit in a steel plate over a distance of about 30 cms. As I have not yet discovered a method of soldering to steel effectively it rather relies on the joiners to act as solder points.

"Tony Polson" wrote

Fair comment, but I wasn't really being critical of your response, just enlarging on it.

John.

The PSE had very steep gradients but the later ones are much less so: Atlantique, Nord, Rhone, Mediterranean and Junction.

The famous Lickey incline could have been avoided, 1 in 37.7, but for cheapness, less distance was involved. Also a shorter steep incline exists linking the two Exeter stations. Bound to be others in the country.

BTW my helix employs @ 1 in 28 and for Hornby 50 the limitation is curvature of the helix rather than the weight of the train precluding long trains.

Chris

Chris

Peter Abraham wrote in news: snipped-for-privacy@4ax.com:

3M 70mm???????

Wots wrong with 3" in 10'? :-)

"Chris" wrote

Aye but the Hornby 50 has exceptional haulage capacity - try running its maximum train with a Hornby Black 5 in charge just as an illustration.

I couldn't get my Black 5 to pull more than 25 wagons on the level, let alone up a steep gradient, so I ain't got one any more. Even the much slated Bachmann WD 2-8-0 is comfortable with 50 wagons in tow.

John.

4mm scale!!! not 1/72

I am 68 years old and have used cgs, MKS and Systême International since I was at primary school in Bristol. Only the US held out and insisted on Slugs and Winchester gallons although the Pascal holds firm here. Proper Engineers can translate effortlessly!

Forget about giving the gradient in Imperial or metric measurements, just quote 1 in whatever, or percentage, and then your unit of measurement can be axehandles, cubits, versts, rods, poles or perches, or as your fancy takes you. Regards, Bill.

Which is why I did!

The North York Moors Railway has a stretch of almost 3 miles between Grosmont and Goathland at 1 in 49, still with steam haulage. The original alignment (still visible) was steeper and was rope-hauled between Grosmont and Beck Hole.

Peter Abraham wrote in news: snipped-for-privacy@4ax.com:

I'm not that old but I have to confess that at my primary and prep schools the pages in our atlases were still mainly tinted in pink, not that my masters were at all old-fashioned but they appeared to regard the last two big ones as minor aberrations in the 1,000 year war with France. Even at senior school there was marked reaction against anything that even hinted of France and that included counting in meter-grams or whatever they are. It being a case of "Well we suppose that sort of thing is fine for engineers and the like but hardly fit for a gentleman".

Seriously, my dad was and is a "proper engineer", hydraulics and pneumatics being his field of expertise naturally he still measures using real measurements rather than those artificial French constructs if for no other reason than the stuff he still does the occasional job on is as old as him, Whitworth Threads on the bolts and all that. :-)

I sometimes smile when in the plumbers because the French do not know that the pipe thread sizes of 3/8; 1/4 and 1/2 etc refer to BSP sizes. Equally, they have no idea that cycle threads are also brit. The German effoerts to take over with their DIN standard merely caused a lot of confusion but has taken over all of the Hydraulic field. I have not in any practical application come across Whitworth or BSF for well over 40 years. In the Military the UNC and UNF were well unstalled by 1960.

Lets not mention where the standard gauge, as used by French railways, comes from shall we. ;o)