The Trials and Tribulations of a course measurer

By Mike Sandford, Measurement Secretary for the South of England

Put the clock back 20 years. I am striving to break 40 minutes for 10k, a quite modest level of athletic performance. I am having the run of my life. The kilometre markers come - each in a shade over 4 minutes. I cross the line in 40mins and 10s, narrowly missing my target. But what if the course was not accurate? At a speed of 4 minutes per km I was running 42 metres in 10s. So if the course was not accurate but had been laid out more than 42 metres long, it would have denied me a sub 40 minute time. However, the course had been officially measured and held a certificate of course accuracy. So there was no doubt despite all that effort I had just failed to achieve my 40 minute target. I never reached that performance level again. Perhaps hell could be an endless series running targets not met. May be heaven could be a series of PBs or even races won.

The secretary of my running club realised there never would be any really useful place for me in the club teams and sent me to train as a course measurer. I suppose I had shown a bit of aptitude when I walked a surveyor's wheel around the club's half marathon route, but the surveyor's wheel is not good enough for official measurement. Since the Bristol Marathon in 1961 the method developed by the late John Jewell and others, has been to use a precisely calibrated bicycle, with a geared counter recording the rotation of the front wheel. One count of the Jones counter is about 10 centimetres. I learnt how it is essential before and after any course measurement to calibrate the bicycle by riding 4 times over straight calibration course about 400 m long which had been itself measured with an accurate 50m steel tape. I passed muster in the practical tests during my two days of training, and embarked on my measuring career.

I have just looked out my report on my first measurement, a 10k course, given course number 1991/204 when my measurement report was accepted by the late Roger Gibbons, who as Course Measurement Secretary for the South of England checked my report and issued the official certificate of course accuracy. The race started and finished less than 1 km from my home. My two rides of that course agreed to within 80 centimetres of one another. To get that level of agreement you have to ride really precisely along the shortest running line, and encounter no significant changes of temperature which cause the bike tyre size to change. I was in measurement heaven.

When conditions are unfavourable it is not possible always to get such good repeatability, but over time I became very confident of being able to measure a 10k well within the 10m measurement error which is allowed to meet the international standard of accuracy for road races (0.1% of the race distance). So much so that, nowadays, I will be completely confident with just a single ride in good conditions, rather than the two rides I needed as a beginner in order to be sure.

Nineteen years later, while I still get a definite kick from the satisfaction of exact results, measurement heaven also comes in other ways:

For example when measuring beautiful rural courses on quiet country lanes early on a summer morning before there is any traffic about, it is easy and safe to take the shortest line with the protection of the race director's vehicle in front or behind as necessary. I always find interesting and admire the work which the race director has to do in preparation for a race and it is fun visiting different races in preparation and seeing something of what goes on behind the scenes in advance of a race.

I was appointed as an international IAAF/AIMS measurer and so I have occasionally measured abroad in nice places: Malta, Jamaica. It is hard to beat relaxing in warm waters after an early morning spent measuring on tropical roads.

Nearer home races seeking AIMS recognition have provided interesting trips to distant parts of Britain from the Loch Ness Marathon to Guernsey for the World Inter-Island Games and other races.

Happily we now have two newly qualified local measurers covering the Channel Islands. The three English regions are fairly well covered at present, but we would like to train more measurers to cope with the increased load as RunBritain develops more races needing measuring. Alan Young the measurement secretary for Scotland is on the lookout for more recruits to train, and I am sure John Glover would welcome help in Northern Ireland.

But it is not all heaven, and most measurers experience measurement hell from time to time. On one trip to Malta a violent winter storm struck and the power was out in the hotel. Riding in the wind was hard work and measuring accuracy was hard to achieve. On another occasion a police escort booked to provide safe passage for me while measuring along a very busy road turned up late and then refused carry out escort duties on safety grounds. I was forced to measure the course in bits and pieces travelling with the traffic and then struggle with the figures to calculate the measurement distance.

Such measurement hell does not just happen abroad. Last winter provided an example nearer home. It is a rather long story, but try and stay with it and follow detail of my agony.....this is what measurement hell involves.

I was called 61 miles away to Gloucestershire - a bit outside my normal patch, but no-one local was available to measure a 20 mile course, and time was running out. It was already January and the race was early March. Every day seemed to threaten frost, snow or ice either on my calibration course at home or 60 miles to the west in Gloucestershire. It was not until mid February that there was any sort of break. I calibrated at home in the dry at a comfortable 7C, at sunset the evening before. Next day my heart sank as snow flurries started on my journey over the Cotswolds along the A40. By the time I arrived the temperature was 1C and a slushy covering was building up on the country lanes. Hoping things would improve later in the day, we drove round in the course director's car. I deployed my GPS to check the distance of the main 5.5mile loop which was to be run 3 times. Even though we cut corners on the quiet roads the GPS can do no more than give a rough indication of the distance - little better, if at all, than I can get by measuring carefully on a large scale map or satellite view. Generally GPS is at least ten times or more worse than the accuracy needed for certifying a course. To judge by the reports from some runners I would say it is more like 50 times worse. However, the loop was looking to be very close to 5.5 miles. So it would mean that the mile point references would occur at half mile intervals, and would be at nearly the same points on the first and third laps.

We then stopped at the course organiser's house and I was fed refreshments while we monitored the weather forecast for the sunny spells that had been promised for that day. But the snow seemed set to last, so rather than waste the trip I decided to get a ride of the loop to establish the length and locate the mile reference points. What started with light sleet and wet roads in the start /finish area gradually deteriorated. Roads became covered with a white slushy covering. I had to ride very carefully to avoid skidding and inaccurate measurement. My glasses misted up. I don't need them to read the Jones counter but my table of counter readings for the mile references was in small print. My notebook got wetter. Eventually I had to turn to a new page to make each each set of notes, then the pages just stuck together. Towards the end of the loop I had to dictate counter readings to the course organiser in his car and he read back to me the target counts for the half mile points. We got back to the start/finish area and I felt that I had done enough to determine the approximate start/finish locations and all I needed to do was to come back in better weather for a final ride and fine adjustment of the start location to make the length exact.

Only when I got back in my car did I realise how cold and wet I had become. It was too late to calibrate at home that day, so my post measurement calibration was done next day, but I could not rely perfectly on the calibrations done on dry surfaces when I had measured on cold slushy ones.

I am always a bit cautious about calculations which I do on the course to convert the counter readings to kilometres or miles, so one of the first things to do at home is to enter everything on a spreadsheet and carefully double check for any mistakes. Every thing looked fine and the loop was about 17 metres more than 5.5 miles, and would probably come out even closer to exactly 5.5 miles if I managed to get a another ride with a more representative calibration. I was pleased with the first day's measuring despite the adverse conditions and looked forward to an easier final day of measuring. The overnight frosts continued but 3 days later I grabbed a break in the weather and repeated the trip obtaining measurements in considerably better conditions (dry 7C - 12C). The loop turned out to be just 6 metres more than 5.5 miles. I adjusted the provisional start to give the correct 20 miles and went home to write my report.

Disaster. I finally had 14 pieces of measurement to add together for the 20 miles, but my spread sheet now showed the distance to be exactly 19.5 miles! In the cold and wet on the first day I had screwed up my counting of the half mile intervals on the 3 laps, what I had labelled in my notebook as the 18.5 mile point was actually the 18 mile point. I needed to add another half mile at the start. Unfortunately when I did the spreadsheet check at the end of my first day I had repeated the same mistake. Now I needed to go back to Gloucestershire for a third time and readjust the start. Fortunately I could plan a start adjustment of half a mile using the satellite view map of the industrial estate, but the organiser got understandably anxious until he could be shown the new location on the ground. For the next two weeks inclement weather continued before we got a good day just 5 days before the race, and another 122 mile round trip and a small amount of riding completed the adjustment. I then had a big measurement report to complete and sent it off to the Measurement Secretary for the Midlands who had been pre-warned to be ready to check it, and he was able to issue the certificate of course accuracy just 2 days before the race. You can see the course map from my report here. Truly, that one is a candidate for my short list of measurements from hell.

I hope I have not painted too bleak a picture of course measurement by describing measurement hell. Think of heaven. Perhaps you would like to find out more about an interesting job that helps ensure races get their distances right. If so, as a first step have a look at our introductory on-line lesson.

Even if you would never consider training to become a measurer, next time you encounter runners comparing their GPS readings and complaining about a course, just remember to ask to see the organiser's certificate of course accuracy, or search for it in the lists at coursemeasurement.org.uk. Also, if necessary ask to see the measurer's course map or the full measurement report and check the course was run as measured. Meanwhile, enjoy your running in licensed road races with courses properly certified, and set some memorable performances which you can trust to have been over accurate distances. Always look out for the logo of the Association of UK Course Measurers to be sure that the course has been measured and has obtained a certificate of course accuracy and that the race organiser has renewed it for the date of the race.

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