Talk:Moelwyn Tunnel

From Festipedia, hosted by the FR Heritage Group
Jump to navigation Jump to search

Old and New Tunnels[edit source]

I am unhappy with these descriptions of the tunnels. Old Moelwyn Tunnel is recorded twice and an entirely extraneous tunnel, nothing to do with FR, is entered beneath. Neither are Roman mining tunnels relevant. From memory the ruling grade of the New Moelwyn Tunnel is 1 in 75 - Adrian has my set of plans - but I am not able definitively to say it is not the 1 in 99? entered. I have deleted the fictitious brick lining of the Old Tunnel (from personal observation) and increased the number of shafts from 1? to 2? I have seen two shafts on top but just wonder if there may have been a third. I never walked right through the Old Tunnel - it was dark, sooty and wet - so only went 50 yards inside it, but have walked the Tunnel Newydd. It was evident later that the plug near the top end did not stop water percolating through the fractured rocks around the tunnel and the Deviationists were able to fill their reservoir from this leakage. Their dam is still there, some yards inside the bottom end of the Old Tunnel.Pnjarvis (talk) 16:53, 10 September 2015 (UTC)

In discussing "rathole" tunnels, it make sense to give more than one example, and since FR has/had only one nasty tunnel, the secondary examples have to come from elsewhere. FarleyBrook (talk) 01:47, 11 September 2015 (UTC)
I'm with Pnjarvis on this one. The old tunnel has 2 entries when it is the same tunnel. The "1863 tunnel" really should be removed. Furthermore, so should non-FR/WHR entries; I do not believe they are appropriate. Tony E. (talk) 07:31, 11 September 2015 (UTC)
I doubt the title 'rathole' ever formed part of the description of Old Moelwyn Tunnel, whatever may have been the vulgar parlance among Deviationists etc. Pnjarvis (talk) 16:06, 11 September 2015 (UTC)
The two versions (horse and steam) of the Old M. Tunnel can be combined, though care must be taken to maintain sortability. FarleyBrook (talk) 02:19, 12 September 2015 (UTC)

There are no "two versions"; it was the same tunnel unaltered.Heritagejim (talk) 08:11, 12 September 2015 (UTC)

The template might also be renamed Template:Tunnels. FarleyBrook (talk) 02:28, 12 September 2015 (UTC)

Sandbox[edit source]

Comparison of Tunnels

N Year Link Gradient Length Curvature Ventilation Width Height Sides Roof Line Remarks Notes
101 1842 Old Moelwyn Tunnel 1 in 80? 730yd N/A N/A 8' 0" 9' 6" Straight Semi-circle Brick?? Replace 1836 inclines Nasty
106 1977 Moelwyn Tunnel 1 in 99? 275yd A B ?? ?? Straight Low arc Shot Concrete
Deviation avoids flooding Comfortable
999 1066 Roman Tunnels, Mining ---- C

Gallery[edit source]

Template view[edit source]

Tunnels and Loading Gauge, etc.[edit source]

Comparison of Tunnels, etc.

N Year Link Gradient Length Curvature Tracks Ventilation Width
Sides Roof Lining Engineer Remarks Notes
Old Moelwyn Tunnel
* Horse Power
+ Steam power
1 in 80? x 730yd Straight 1 3 8' 0" 9' 6" Straight roughly Semi-circle Stone portals; unlined within J. Spooner Replaced 1836 inclines
* No Problems
+ Nasty, confined, wet
106 1977 New Moelwyn Tunnel 1 in 80? x 275yd Straight 1 None 11'
(+/- 3")
(+/- 6")
Straight Low arc Shot Concrete
M.A. Schumann;
the Three Miners
Deviation avoids flooding Comfortable
201 1851 Garnedd Tunnel 1 in 80; dips under portals 60yd Slightly curved 1 No 8' 0" ca.10' roughly straight Semi-circle, stone portals Mostly unlined; brick piers in places J. Spooner Deviation of 1836 route
701 1836 FR Structure gauge 8' 0" various cuttings, now less; was ca.7' at Cemetery 1963 8' 6" (to 1956) but 9' 8"(since 1963) Rhiw Plas Smallest bridge or tunnel GS
705 1836 FR Loading gauge 6' 2" plus in-swing at carriage centres 9ft +/- 3ins Largest rolling stock GL
  • Notes: N/A = Not Available.
  • x Notes: Ruling Grade about 1 in 80.
  • + Notes: At ruling gradient.
  • $ Notes: Structure gauge and loading gauge are not simple rectangles.

Gallery[edit source]

Rathole[edit source]

A rathole tunnel is so-called when a combination of factors make it difficult, unpleasant, and even dangerous to operate, including

  • gradient too close to the ruling gradient.
  • length longer than the "momentum distance".
  • wet rails from steam and/or water seepage.
  • unhelpful wind direction.
  • train load too close to full load.
  • loading gauge too close to the structure gauge.
  • awkward stop at bottom of tunnel.
  • insufficient time between trains for smoke to clear.
  • single line rather than double line.
  • lack of escape route for crew in case of stall.
  • even great engineers made mistakes and rathole tunnels.

There is a standing instruction to enginemen on the FR that in the event of the engine coming to a stand in a tunnel, the train must run back by gravity outside the tunnel before any effort is made to blow up steam.

By FarleyBrook (talk) 04:01, 16 August 2015 (UTC)