I wouldn't have liked to have attempted this without using a spreadsheet (or maybe even a short program - looks like you're comment from RC3 was serious!)
I'm worried about the conversion factors that you have used though.  The first instruction given is inches (isn't it?), so works out to be 0.33km, which is 12992.12598 inches, not far out (just 0.0019%), but if you're quoting 10 sig fig, then it's quite a difference as your answers are only correct to 6 sig fig.  The true conversion factor is 1 yd = 0.8144 m exactly (as the yard is now defined in terms of the SI system), and inches, feet, chains, furlongs, miles are all defined as multiples of these, though I guess you did that, as the error is consistent for these units.  Not too sure about fathoms or nautical miles as I couldn't find exact definitions of them.  Is a fathom exactly 2 yards, and the best I found for a nautical mile was 1852m.  The route seems to break down in a couple of places, before 202 and after 172 but I think I've got a good route.  It seems a bit tricky around 185 (almost went W instead of E), but I think that's down to me not being able to find a good definition of the fathom, as all my conversions were 0.3% out from yours.
PS Sorry to be so scientific on all this, but I am an engineering student after all. [First answers received and 9/10. Students must have a lot of spare time on their hands?] Steve Brumpton

SH226 is only just on route - if you keep hard to the left hand verge you could squeeze past it - in which case the next square where you join a white is 1992. Since leaving it to the last minute obviously didn't help me last time (RC5 disaster - compounded by not starting at the right spot height -duh) I thought I'd send this in fairly early. Also, is the clue 1563.864016 (yds) supposed to result in 1.63 km instead of 1.43 km? (leading to SH202 from GS 1694). What conversion factors did you use for the fathoms and nautical miles? I had to use a fiddle factor to convert from the figures in my dictionary! I suppose I could of course have it all completely wrong..... Thank God for spreadsheets is all else I can say![What can I say? 10 points!] Ian Buxton

What a swine! I never knew there were so many imperial units!! I got it to work using Furlongs, Fathoms, Feet, Inches, Yards, Miles, Nautical Miles and Chains. I also calculated Cables, Hands, Nautical leagues, Statute Leagues, Links, Paces, Points, Spans and Rods!! (I also found something called micro-fortnights!)
Took me ages to realise the first distance was from the first junction not the control! I nearly made it work for distances between gradient arrows, distances from the nearest corner in a grid square to where the road exited and many others...
I think one of your numbers was wrong - 1563.864016 translated into 1.43 KM when using yards - I think it should have been 1.63KM, but by then it didn't really matter!
After this, I hesitate to think what you will throw at us next! [Another 10 points!] Mark Goodman

I think there is a mistake about 2/3 of the way through (1563.864016) but by then it was easy to find the next plot. Very time consuming but otherwise OK and a bit different. [10 again!] Ted Manktelow

Very enjoyable. Not sure the route I found is correct. Got a tad lost around plot 26 (1563.864016) but eventually managed to find 10 answers [10 points - This is all too easy!] Ewan Hopes

I could not seem to convert 1563.864... properly. My conversion to fathoms seemed a fraction different (and not exactly double the yard factor!) [Guess what? 10/10] Colin Hensman

I'm not sure about the 1563.864016 - either I've got everything else wrong, or it should be about 3.3km, not 2.86 (i.e. 1804 yds rather than 1563) is the third 'f' fathoms? - there are some I couldn't work out as fathoms of exactly 6 feet, but were about that long. And presumably a white/white junction doesn't count as joining a white [Correct], esp if one side of the T is no through - otherwise RC 8 is 1899 and the ones after get moved up. [A boring 10]  Clive George

Ran out of time (been a bit busy). This was the most difficult routecard so far, so difficult in fact, that I didn't even get past the first junction. Hopefully this will only be a minor hiccup and things will get back to normal on the next routecard.  Mike Biss

I can only get this to work if I assume that the 25th number should be 1782.56831 (giving 1.63km instead of 1.43km).  Also, I think you got the conversion factor for fathoms wrong - 548.8056 instead of 546.8056 [Only 10]   Mark Fearon

*&$%$(%*$&!!!!!!! Too hard!! Didn't have enough time... I got about the first half-a-dozen instructions, but not enough route to even get one answer!! Won't have much time next week, either - please, please, make it easier again!!! [I can't really, yet, otherwise we'll end up with all the competitors scoring a maximum of 120 points. Then again, I don't want to frighten off people from taking part - I can't win!]
As for the previous routecard: I assumed, as did others, that a ford was where the blue line was unbroken across the road. OK, I didn't read the instructions. But I really don't think you should let some people get away with it and not others - and then, by saying you'll amend the rules, imply you were wrong in the first place! How about allowing either 2 or 4 as the answer to the ford RC? This would seem to be a fair compromise...[There were only three competitors who potentially gave a "wrong" answer. Two queried their own efforts (see Competitor's Comments RC5), giving an alternative correct answer, subject to what I was looking for. This was the right approach. There will always be different theories as to route choice and answers, that's why I encourage supporting comments to justify alternative, reasonable, interpretations.]
Personally, I would prefer the routecard issue to continue as it is: I don't have internet access during the week at all [er..., but, this e-mail arrived on Thursday evening!?], so with the new arrangement I'll get one weekend only. However, I appreciate that if the majority of entrants are lucky enough to play around at work, I'll have to lump it! I think Dave Bell's suggestion regarding routecard timing is best...[see my response in the latest version of RC5 comments]   Catherine Woodman

I wish you did not keep asking questions about whites, with my failing eyesight I can't tell white from yellow anymore. And by the way want to borrow a ruler?  Pete James

Hmm, I'm going to have to give up either my job or all my hobbies if they all take as long as this one! I think anyone who did this without a spreadsheet deserves a medal. I assume clue number 26 is just wrong? Nearly gave me a nervous breakdown that!  Jeremy Rodgers

Sorry, I've given up on this one! No computer or calculator to assist, only some ancient log tables and after half a dozen junctions decided furlongs, fathoms, feet, yards, chains, miles, nautical miles, rods, poles or perches were too much to do by hand! (since I've a house and family to fit between junctions!) Looking forward to the next.  Carol Moulton

This was the really nasty one you promised - or are there worse to come. [With the quality of answers I'm getting, including yours, Yes!] As a non-computer man I would say try this (as I did) with a pencil, reams of paper and a seven figure calculator. 1 week later - and I could have got Mike working on his computer in Texas. It didn't help that I could find 11 non-metrics - inch, foot, yard, fathom, rod pole or perch, chains, cable, furlong, mile, nautical mile and league. (at least I found the 3 f's) The middle bit of the route gets a bit hairy, but I'm happy with the beginning and end. Unfortunately, the sequential questioning means that one answer in the wrong place can bitch up the lot. But can't grumble about that as its obviously your way of sorting out the boys from the men. Think I'm about 10 years old! [10 is significant - that's how many points you got!] I've had to rush this, as I still haven't done my packing and I leave early Saturday morning. I look forward to trying the internet  on Saturday evening. [Flying to Texas to use the Internet just for this competition is a bit excessive though!]   Don Clarke

The answers in the form assume that you want the even valued spotheights. If you wanted the 2nd 4th 6th etc SH crossed then the first five RC's are 191, 118, 202, 185, 94. The grid squares are unchanged. Also clue 1563.864016 appears to be a little out. Hope I'm not being too pedantic.  Keith Norman

If this Section sorts the men/women from the boys/girls, count me in with the babes-in-arms!  No joy apart from over a dozen non-metric measures (3 starting with 'F') which did not seem to lead to any coherent plotting - solution awaited with interest.
Whichever day is chosen for publishing the Route Cards, my irregular diary means that I shall have several truncated weeks as well as some holiday weeks which will be a complete miss.  I marginally prefer the original Saturday proposal to Wednesdays but I like Dave Bell's long weekend suggestion better still! [see my reply to this in RC5 comments] Peter George

I give up. Too many variables!  Alan Crabtree

Bit of a tease! Only real doubt is whether SH 226 in 1694 is on the route or above the junction, if it is off route then my answers would be 118, 202, 172, 94, 1901, 1998, 1797, 1695, 1991 and 1892. [Keeping up his uninterrupted run of 10 pointers] Dave Bell

I couldnt FATHOM it out even when I INCHED my FEET along the MILES of road, FURaLONG time I seemed to be in CHAINS wishing I could convert N.MILES into Yards. [10 points just for the comments] Got stuck at 1563.864016 but then managed to work backwards after I read latest news bulletin (7) and knew start of route card 7.  Dave Keetley

Answer 2 (Spot Height 226) is on the junction but I have assumed that the route passed through it, since the rules do not specify how to determine this. If you do not pass through this spot height, then answers 3 to 10 are shuffled up one and answer 10 is 1992. Although I am not sure, I have taken the junctions in GS 2000 (northern junction) and 1991 (North Eastern junction) to be both crossroads, because then it fits. The number 1563.864016 appears to be wrong, and should work out to approximately 1.62 km, the nearest possibility is 1.43. I did not manage to work out how you got to your upto ten significant digit answers from kilometres measured to 2 dp, but it all seemed to fit, and I finish near the start of the next one, so I assume I've done it right. I used inches, feet, yards, fathoms, chains, furlongs, miles and nautical miles in the end, but I also considered hands, rods, palms, spans, cubits, leagues cables, angstroms, barleycorns, ells, ems, light years, links, parsecs, picas and points. [10/10 for finding more non-metrics than anyone else!] I now know far more about the imperial measurement system than I did before. How educational!   Matthew Atkinson