T' La'al Ratty MAPS HEIGHTS 19-20 April 2019 |
Where ? Map Heights Figures Timing Track Finally History Read Me |
The 15in gauge R&ER (La'al Ratty) is about 7 miles long, and uses most of the track bed of the original 3ft gauge mineral line (Owd Ratty). Starting in Ravenglass at about 15 m above sea level, the line skirts around the northern foot of Muncaster Fell and then around the southern flank of Blea Tarn Hill to reach Dalegarth (for Boot) at 52 m above sea level. On the way, the line gets close to sea level, shortly after Ravenglass, and then, shortly before Dalegarth, reaches a maximum of about 58 m above sea level. While minerals, especially iron ore, were the original raison d'être of Owd Ratty, today, tourism reigns supreme, visitors being attracted in part by the scenery through which the line passes.
Now prepare ye for some plots and graphs. Not too overwhelming, but hopefully quite interesting! You will see here:
Ravenglass is on the Irish Sea coast and is the western terminus of the R&ER. Ravenglass lies about 240 miles or 358 Km NW/NNW of the centre of London. The centre of London is officially taken as the intersection of The Strand, Whitehall and Cockspur Street. This intersection is often referred to as Charing Cross, not to be confused with the nearby Victorian Eleanor Cross itself, nor the station in front of which the cross stands. The detailed figures, for the fun of it, are as shown below.
Our "straight line" distances are actually "great circle" distances on the earth's surface. We assume the earth to be spherical, which is not far off the mark. Assuming the earth to be a sphere gives us a maximum error of about 0.1% in our distance values. Not that much really! Can't complain! Indeed, we can speak of the distances as the "hypothetical crow" (cornix hypothetica) flies.
From Ravenglass the R&ER wends snakes its way around the northern foot of Muncaster Fell and then follows the River Esk, eventually reaching Dalegarth after Blea Tarn Hill. This is a distance of about 7 miles. In the map, the minus signs for the longitude angles indicate "degrees west of Greenwich". The map grid scales translate to 1.112 Km per 0.01° latitude and a mean of 0.648 Km per 0.01° longitude, all when using 6371.0 Km as the volumetric mean radius of the earth - as per the WGS84 standard! In Guildford, in Surrey, the longitude scale is more (as expected), with a mean of 0.697 Km per 0.01° longitude; in fact, it is 49 metres per 0.01° longitude more than in Ravenglass!
Because we don't live on a flat earth - unless you are a convinced "flat-earther" - maps are inevitably a distortion of what is. In other words, it's all a matter of mapping a curvaceous surface onto a flat surface. In our case, the northern length of our map grid is stretched out by an extra 0.12 %, to make it the same on the page as the length of the southern part of our map grid. Not that much for our purposes really! Can't complain!
The R&ER climbs from about sea level to 58m, and shortly afterwards reaches Dalegarth at 52 m. To smooth out possible measurement errors, I have superimposed a "5th order fit" on the height plot. The main climb is between 1 Km and 5.5 Km from Ravenglass. All achievable with R&ER's steam power!
The above plot uses a true origin for the vertical elevation (height) axis, so as not to lose track of reality. What a worthy aim!
Here are some "vital statistics" in metric and imperial units. The total length of the journey is 7 miles or about 11¼ Km. It's not a completely smooth climb from Ravenglass to Dalegarth, so the total ascent exceeds the difference between maximum and minimum elevations; I'd suspect things, if the reverse transpired!
It's one thing to discuss the terrain over which we travel, but it's quite another to consider how the locomotives - steam and diesel - respond to travelling with a train of nine, possibly fully laden, carriages over that terrain.
It takes about 40 minutes to travel the full length of 7 miles. We can assume a stop of about 5 minutes at passing points. We shall further assume just one passing point - at Irton Road. This gives a total speed of 7 miles per (40-5) minutes or (7x60/35) mph. In other words, 12 mph! This allows passengers time to appreciate the interesting landscape as it glides past them.
If you are keen to see the railway route superimposed on an Ordnance Survey® (OS) map, then you can use the following file to do so. The numerical data in this file were plotted by me. Hence the data are presented on a "best efforts" basis.
Any map is an approximate representation of what is. Practicality and scale are relevant considerations. We are not dealing with a planning application calling for detailed spatial descriptions of intricate boundaries. However, notwithstanding, I hope my humble endeavours on this page are nevertheless interesting for, and useful to, you my reader!
Here I have added two excerpts from old maps, excerpts which highlight the presence of "Owd Ratty" in Boot and its immediate neighbourhood. The Ordnance_Survey® maps are sourced from the Map Section of the National Library of Scotland (NLS) (Link), who state the restrictions in place on the commercial re-use of these maps.