Features of Our Walk from Sevenoaks to Eynsford

This 8.8 mile (14 Km) "linear" walk was ably led by Peter. The heights stayed within a band of 39 to 107 metres, but with an overall gradual descent from a starting height of 100 m to a final height of 60 m above mean sea level; however, there were quite a few "ups" and "downs", providing interest and good exercise. Walking weather was favourable, with moderate mid-July temperatures and with sunshine and some clouds for the whole day. Despite a start of about 10:30 am, we completed the walk comfortably - it was July and daylight was not at a premium.

As we approached Eynsford, our destination, we were welcomed by this pleasant North Downs landscape, unbelievably close to the south eastern reaches of London. Plans for an airport in this area nevr reached fruition, and probably never will!

Now prepare ye for some plots and graphs. Not too overwhelming, but hopefully quite interesting! You will see here:

• An Outline Map of Our Walk
• Height Profile of Our Walk
• Some Facts and Figures
• Average Rising and Falling Gradients
• Less Quantifiable Considerations
• Timing & Speed
• Track File
• Postscript

Outline Map of Our Walk from Sevenoaks to Eynsford

Our linear walk was roughly south to north. In the map, the grid scales translate to 1.112 Km per 0.01° latitude and a mean of 0.689 Km per 0.01° longitude, all when using 6371.0 Km as the volumetric mean radius of the earth - as per the WGS84 standard!

It may have been possible to reduce the amount of road walking on the northern outskirts of Sevenoaks. An off-road deviation was mooted but did not find any takers - perhaps next time.

This walk has many facets, both scenic and historical. It would thus be a pity to opt out before completing the full walk, especially after making every effort to join the walk at the start. However, for insistent "opt-outers", the respective positions of Otford, Shoreham and Eynsford stations offer possibilities for those determined to escape from this attractive walk - but who would!

Outline Map of Walk

I plotted our walk by hand on my return home. Of course, I tried to be reasonably accurate. Even OS maps, on which I based my plot, may not show all the required detail, but appear to give the requisite degree of accuracy in this case.

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. We don't want to carry curvaceous representations of the terrain on our walks, do we? In our case, the northern length of our map grid is stretched out by something like an extra 0.20 %, to make it the same on the page as the length of the southern part of our map grid. Not that much for hiking purposes really! Can't complain.

Height Profile of Our Walk

It's of course fine to say that we reached a maximum height above mean sea level of about 107 m, but what's the significance of that? I mean, we started at 100 m and finished at 60 m. Probably, of greater interest when it comes to considering personal achievements, is the total ascent, which usually requires greater effort than the descent. On today's walk, the total ascent was 193 m. In addition, the total decent was 233 m, which as expected, was greater than the difference of 40 metres between maximum and minimum heights above mean sea level.

Height Profile

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!

Some Facts and Figures

Here are some "vital statistics" in metric and imperial units. The total length of the walk is measured on a conceptual "flat" plane at mean sea level, WGS84 style. Of course, as mentioned above, the total descent exceeds the difference between maximum and minimum elevations; I'd suspect things, if the reverse transpired!

"Walk facts and figures"

Average Rising and Falling Gradients

And here, for the numerical fun of it, are the average gradients we overcame on our walk. The rising and falling (negative) gradients are both averaged over the distance given, with level stretches having rises and falls of less than ± ½ metre.

Rising and Falling Gradients

By comparison, Hertfordshire County Council recommends that its roads should not have longitudinal gradients of more than 5% and one of the steepest adhesion railways in the world, in Austria, has a maximum gradient of 11.6%. By way of further interest, the clockwise route of the Fairfield Horseshoe in the Lake District has a total distance of 15.62 Km (9.71 miles), with the following calculations: an average rising gradient of 14.66% over 6.589 Km, a level part over 0.345 Km, and an average falling gradient of 11.11% over 8.676 Km. This is seen by many as really quite challenging - but then, when you compare it with our walk, it can be said that we had a more leisurely and less demanding aim compared with Lakeland challenges!

Less Quantifiable Considerations

On any walk there are considerations which are very real but tantalizingly out of ready reach of those who wish to espouse a numerical approach to many of life's activities. Here are three considerations for starters.

• Weather: We had good summer walking weather. It stayed dry and we had sunshine with some clouds. It was good walking temperature, but the exact figures elude me!
• Ground Conditions: These were very good - so far it had not been an unduly wet summer.!
• Signposting: This was mainly of the type "here's a bridal path" or "here's a foot path". Actual destinations were not over liberally sprinkled amongst the sign post population, but some of us had maps anyway!

Timing and Speed

It's one thing to discuss the terrain over which we walk. It's quite another to ask how we personally respond to walking over that terrain. There are a number of considerations, of which timing and speed can be taken as starting points.

• Timing: The walk started at about 10:30, which allowed for a comfortable start, considering the need for Sunday morning travel. There was a finish time of about 18:00 for those that did not wish to savour the delights of the "watering hole" in Eynsford. Of course, it was high summer, so day light was not at a premium.
• Speed: If the walk started at 10:30 and finished at 18:00, with 1½ hours for our lunch break, this gives six hours actual walking time. For a distance approaching 11.79 miles, we then get a walking speed approaching 2 mph. This was less than your average walking speed of 2½ mph, but allowed for more comfort, socialising and appreciation of the landscape. Very nice!

Track File

If you are keen to see our walk superimposed on an Ordnance Survey® (OS) map, then you can use the following file to do so. As mentioned above, the numerical data in this file have been hand-plotted by me (no GPS!) on my return home. The data are based on WGS84. Of course, for copyright reasons, I do not show the OS-based map here.

• Sevenoaks to Eynsford

Postscript

Any map is an approximate representation of what is, and my plotting thereon certainly is. Practicality and scale are relevant considerations. We are not dealing with a planning application calling for detailed spatial descriptions of intricate boundaries. For us in the hiking community, the degrees of accuracy and precision should be just enough to give us useable and helpful knowledge of the terrain about us and beneath our feet. I hope my humble endeavours on this page are in this respect interesting for, and useful to, you my reader!