How close should a platform edge be from the track

[hayfield]

I am about to lay some track and am wondering how close the platform edge can be. I am modelling to 4 mm scale EM gauge and have seen it quoted that the platform edge should be no closer than 10 mm away from the rail centre. GWR & SR locos with outside cylinders will be used. The platforms are on straight track with the approach also track being straight

Thanks

[Philou]

@hayfield, hello,

 

Would this help?

 

 

EM dimensions are in the R/H column. The acid test, will, as always, be when you run your widest stock through the platform.

 

Note: The 10mm dimension is from the inside of nearest rail NOT track centre.

 

Cheers,

 

Philip

Edited November 18, 2019 by Philou
Clarifying 10mm dimension mentioned in OP's post.

[The Johnster]

As close as you can get them without the stock fouling.  Tape a felt tip pen to the widest part of the cylinders of your GW locos so that the tips draw on the baseboard, and run them through the platform roads (push gently to slide them if the layout's not wired up yet.  Use the line as the position for the platform side wall, as it has given you half the diameter of the pen clearance, about 2mm.  Extend the top edge of the platform surface out about 1mm towards the track from that and you should be fine.  Your Southern locos are not as wide across the cylinders as GW ones.

 

Curves, and platforms on curves, are a whole nother can of worms.  Here the problem is the length of the vehicles and overhang, outwards at the ends and inwards in the middle.  You need two different colours of felt tip pens for this trick; tape one to the centre of the longest vehicle, probably a coach unless you're running class 40s or Peaks, or Bulleid Diesel Electrics, and the other to the end corner.  Push the coach around the curve drawing the lines.  Again, this gives clearance of half the diameter of the pen, but will be further back from the rail centre than the loco cylinder pen on straight track.  If you are going to be running trains through a curved platform at speed, I'd use this line as the edge limit.

[hayfield]

Philip

 

Thanks, I got my info from a similar source with a different selection of scales. I was hoping to avoid a test bed, think I better make one as the outside cylinders of some locos worry me, but it may be the Ramps which are more likely to cause issues

[hayfield]

4 minutes ago, The Johnster said:

As close as you can get them without the stock fouling.  Tape a felt tip pen to the widest part of the cylinders of your GW locos so that the tips draw on the baseboard, and run them through the platform roads (push gently to slide them if the layout's not wired up yet.  Use the line as the position for the platform side wall, as it has given you half the diameter of the pen clearance, about 2mm.  Extend the top edge of the platform surface out about 1mm towards the track from that and you should be fine.  Your Southern locos are not as wide across the cylinders as GW ones.

 

Curves, and platforms on curves, are a whole nother can of worms.  Here the problem is the length of the vehicles and overhang, outwards at the ends and inwards in the middle.  You need two different colours of felt tip pens for this trick; tape one to the centre of the longest vehicle, probably a coach unless you're running class 40s or Peaks, or Bulleid Diesel Electrics, and the other to the end corner.  Push the coach around the curve drawing the lines.  Again, this gives clearance of half the diameter of the pen, but will be further back from the rail centre than the loco cylinder pen on straight track.  If you are going to be running trains through a curved platform at speed, I'd use this line as the edge limit.

 

 

Thanks for the advice, both the platforms and approach are straight, also a branch line terminus, though there is a crossover between two tracks

[Harlequin]

Obviously the crossover will be the limiting factor. Could you draw it in Templot and get the program to sweep out the bounds of a loco turning through the crossover to find the clearances required?

@martin_wynne Can Templot do that?

 

Edited November 18, 2019 by Harlequin

[gordon s]

John no problem checking it on Templot. What is the format for the turnout. B7 etc?

 

Single or double track? If double what is the spacing?
 

You can certainly run MK 1 coaches in Templot to check overhangs on corners. Not sure if locos are included. No doubt Martin can answer.

 

 

Edited November 18, 2019 by gordon s

[martin_wynne]

Hi John,

 

The answer is 4ft-9in from the centre-line of the track to the platform edge. That's 19mm in 00/EM/P4. Templot can add the platforms to the template if you want.

 

39 minutes ago, Harlequin said:

 Could you draw it in Templot and get the program to sweep out the bounds of a loco turning through the crossover to find the clearances required? Can Templot do that?

 

Yes, Templot can do that. I will post a screenshot shortly. What size are the turnouts in the crossover? What are the loco dimensions? Overall length, fixed wheelbase, width of buffer beams, width over cylinders, distance from leading axle to front of cylinder.

 

cheers,

 

Martin.

Edited November 18, 2019 by martin_wynne

[martin_wynne]

Here's a Templot screenshot showing the platform infringement for a typical bogie coach. The yellow shows the actual body envelope, purple is the recommended minimum clearance. The reduced platform width could be measured using the ruler tool, or the mouse cross-hairs on the trackpad grid.

 

 

This is a B-7 turnout in EM.

 

More info about this function at: http://85a.co.uk/forum/view_topic.php?id=3085&forum_id=1#p22110

 

cheers,

 

Martin.

Edited November 18, 2019 by martin_wynne
link added

[sharris]

2 hours ago, Philou said:

...

EM dimensions are in the R/H column. The acid test, will, as always, be when you run your widest stock through the platform.

 

Note: The 10mm dimension is from the inside of nearest rail NOT track centre.

 

Philip,

 

do you know if this table assumes that apart from track gauge all other aspects of the model are perfect? Is extra space likely to be needed for over-wide cylinders on account of EM and 00 wheels being a little thick?

 

Asking as someone else trying to place platforms at them moment- all the locos I'm currently bodging together are inside cylindered, but I have my eye on some outside cylinder locos in the future.

 

[TheSignalEngineer]

In the 1:1 world some platforms had the edge stones set back about 3" when there was a turnout in the platform to take account of the end throw.

 

Just about visible to the right in this photo https://www.warwickshirerailways.com/gwr/gwrbsh1245.htm

[Philou]

@sharris

 

I think The Johnster probably gave some pointers regarding outside cylindered locos above. Seemingly GWR-type locos were probably a little more generous in that respect (a hang-over from broad gauge days at a guess) compared to other locos. The chart is quite old (can't remember where it came from) and seems to have converted the dimensions from 1:1 for use at the more popular scales. I have successfully narrowed 16.5mm double track to a 45mm centre to centre (the 'six-foot') without any ill effects regarding stock entering or leaving the 'main' line via medium radius turnouts i.e. no side swiping. Gordon s (also above) did kindly give me advice on increasing the 'six-foot' when it came to double track curves. The reduced 'six-foot' (45mm centres) will work with radii above 7ft (approx 2.0m). This I have to test and will report back later - er - well, early next year that is.

 

IF you're constructing platforms on curves, then DO check via Johnster's method above - it only takes a few minutes to set up and will avoid the wailing and gnashing of teeth later.

 

Cheers,

 

Philip

 

[The Johnster]

It is often stated that the more generous loading gauge of the GW is a legacy of broad gauge days, and this must be a major factor, but the railway built many routes that were always narrow gauge from new, but accommodated the larger width gauge.  The broad gauge was a memory by the time the GW was building outside cylinder locos under Churchward anyway. The use of GW locos on through trains to the Great Central, sometimes as far as Nottingham, was due to that railway being constructed to the European loading gauge, though the locos and stock were compatible with the standard British loading gauge.  

 

The GW had running powers on other railways and was involved in several joint railways, such as the North to West route, which must have also been compatible with the GW width gauge.

 

Not sure what arrangements were in place between Exeter and Plymouth on the LSW route but a reciprocal arrangement between the companies allowed each other's route to be used should diversion be necessary.  GW loading gauge outside cylinder locos were used after the grouping on absorbed and constituent railways in South Wales as well, so some easing of the gauge must have been required for this to happen.  It happened before that in some cases; the Rhondda and Swansea Bay was supplied with 3 brand new Churchward small prairies direct from Swindon and painted in their very attractive red livery, taken back into GW stock at the grouping and given their original allocated GW numbers.  There were also some 31xx large prairies lent to the Barry for it's Cardiff suburban traffic, but these remained in GW stock and livery.

 

So clearances on the R & SB and Barry must have been sufficient for those GW locos to run on them.

[DCB]

7 hours ago, Philou said:

@hayfield, hello,

 

Would this help?

 

 

EM dimensions are in the R/H column. The acid test, will, as always, be when you run your widest stock through the platform.

 

Note: The 10mm dimension is from the inside of nearest rail NOT track centre.

 

Cheers,

 

Philip

Ah ha, so this is where the excessively high platforms come from,    It shows platforms dead in line with  buffer centre line at 3ft 6" whereas few exceed  3ft.

Platform edges seldom exceed 3" but even then the figure should 3ft from rail to top of the platform.

I would allow 20mm from the track centre line for GW locos, they are the best part of 9ft 0r 36mm over cylinders and often crab slightly so 20mm should keep them clear, That is very close to 10mm from the rail centre line in post#1 on the other hand GW locos sometimes grazed platform edges anyway.

A bigger problem is laying track straight.   So many layouts have track like a dogs hind leg, fine for modern image but in steam era it was done by eye and generally looked arrow straight, any irregularities will cause stock to rock and possibly strike the platform edge

[The Johnster]

It is often advantageous to have platforms a little lower than scale (some real platforms involve quite a step up into the train anyway) as this means that an optical illusion is created making the platform look wider and longer.  Tapering it subtly away from your viewpoint can do this as well.

[Steamport Southport]

Borrow a Rapido APT. That will sort out any platform clearances. 

 

Seriously I had to dismantle most of the loft layout as it would have hit virtually everything. Even things which a Lima HST and scale length MK3s could negotiate easily were now obstacles. It can get around 2nd radius curves and even tilts, but it's the massive overhang at the front that is the problem.

 

Out of the steam locos, I always remember the old Hornby/Triang Hall was the worst for clearance.

 

 

 

Jason

[Steamport Southport]

2 hours ago, The Johnster said:

It is often stated that the more generous loading gauge of the GW is a legacy of broad gauge days, and this must be a major factor, but the railway built many routes that were always narrow gauge from new, but accommodated the larger width gauge.  The broad gauge was a memory by the time the GW was building outside cylinder locos under Churchward anyway. The use of GW locos on through trains to the Great Central, sometimes as far as Nottingham, was due to that railway being constructed to the European loading gauge, though the locos and stock were compatible with the standard British loading gauge.  

 

The GW had running powers on other railways and was involved in several joint railways, such as the North to West route, which must have also been compatible with the GW width gauge.

 

Not sure what arrangements were in place between Exeter and Plymouth on the LSW route but a reciprocal arrangement between the companies allowed each other's route to be used should diversion be necessary.  GW loading gauge outside cylinder locos were used after the grouping on absorbed and constituent railways in South Wales as well, so some easing of the gauge must have been required for this to happen.  It happened before that in some cases; the Rhondda and Swansea Bay was supplied with 3 brand new Churchward small prairies direct from Swindon and painted in their very attractive red livery, taken back into GW stock at the grouping and given their original allocated GW numbers.  There were also some 31xx large prairies lent to the Barry for it's Cardiff suburban traffic, but these remained in GW stock and livery.

 

So clearances on the R & SB and Barry must have been sufficient for those GW locos to run on them.

 

They were also fine on some parts of the LNWR.

 

The problem with the Grange (6858 Woolston Grange) was they were regulars as far as Leicester, Nottingham and Sheffield, but somebody made a boo boo and rostered it to continue to Leeds via the L&YR where it hit the platform at Penistone (or possibly Berry Brow) and had to be taken off at Huddersfield with a damaged cylinder.

 

https://www.rail-online.co.uk/p603346219/hC26061EF#hc26061ef

 

 

 

Jason

[doilum]

4 hours ago, Steamport Southport said:

Borrow a Rapido APT. That will sort out any platform clearances. 

 

Seriously I had to dismantle most of the loft layout as it would have hit virtually everything. Even things which a Lima HST and scale length MK3s could negotiate easily were now obstacles. It can get around 2nd radius curves and even tilts, but it's the massive overhang at the front that is the problem.

 

Out of the steam locos, I always remember the old Hornby/Triang Hall was the worst for clearance.

 

 

 

Jason

Worse than a crab?

[Pete the Elaner]

6 hours ago, Steamport Southport said:

Borrow a Rapido APT. That will sort out any platform clearances. 

 

Seriously I had to dismantle most of the loft layout as it would have hit virtually everything. Even things which a Lima HST and scale length MK3s could negotiate easily were now obstacles. It can get around 2nd radius curves and even tilts, but it's the massive overhang at the front that is the problem.

 

Out of the steam locos, I always remember the old Hornby/Triang Hall was the worst for clearance.

 

 

 

Jason

According to Kit (Mr Tilt), who worked on it & has a lot of interesting stories about it, the real thing was very limited on where it could run.

There was 1 location (on the MML I think) where they had to run it wrong line to get through a station & even then they drove it very slowly to avoid a platform collision.

I won't allow my E-train on my inside main line if there is something running in the other direction in case it gets a nose job. 

[hayfield]

Thanks all this has been very useful an informative

[Philou]

@DavidCBroad

 

I hadn't looked at the platform height in the chart (though it does say maximum) as I had always understood that it was 2'9" (perhaps it was a minimum) and I've always worked to 11mm above rail height - which seems OK model-wise.

 

Cheers,

 

Philip

 

PS: I do have this drawing with dimensions that shows 12mm maximum height of platform above rail height. It shows other dimensions that may be of use regarding civil engineering works - again I'd don't remember where I got it from.

 

[The Johnster]

12 hours ago, Steamport Southport said:

The problem with the Grange (6858 Woolston Grange) was they were regulars as far as Leicester, Nottingham and Sheffield, but somebody made a boo boo and rostered it to continue to Leeds via the L&YR where it hit the platform at Penistone (or possibly Berry Brow) and had to be taken off at Huddersfield with a damaged cylinder.

 

Pretty serious boo boo and they were lucky that the outcome was only a damaged cylinder, more than enough to scrap a Grange in 1964.  I doubt that the Grange was actually rostered north of Sheffield in the sense of being booked to run through, though, and reckon the most likely scenario is that there was no replacement available there and Control authorised the loco's working through ad hoc, which would make them responsible for the boo boo. 

[TheSignalEngineer]

 

@DavidCBroad

Not surprised that there's no gap between the locos in the top picture. Track centres in 12in to the foot are approx 11ft 2ins so at 4mm scale wouid be 45mm. 38mm would be about right at 3.5mm. Do you model in HO?

Edited November 19, 2019 by TheSignalEngineer

[hayfield]

Thanks again all comments have been very useful an informative. I have spent the afternoon finding the platform function in Templot and used it trying the cleariances with a GWR Mogul, all is now fine thank you all

 

The dummy vehicle program worked well, but in reality the crossover is for engine release only, again the mogul was tested.

 

Thanks to everyone's assistance I now have answered my queries and going on to the next phase  

[sharris]

3 hours ago, TheSignalEngineer said:

 

@DavidCBroad

Not surprised that there's no gap between the locos in the top picture. Track centres in 12in to the foot are approx 11ft 2ins so at 4mm scale wouid be 45mm. 38mm would be about right at 3.5mm. Do you model in HO?

 

38mm is cutting it a bit fine even for H0 (it scales up to about 10'10").