These days spreading practice on the roads is no longer a straightforward affair, and performance of the salt and calibration of the spinner are essential in providing the public with the optimal protection during those hazardous cold spots. Measuring spreader performance is vital in this day and age, particularly, given last year’s winter, when there were serious shortages of salt, all over the UK. However, spreader manufacturer Romaquip now boasts its own testing facility where spread patterns and snaking can be assessed.
Salt is an extremely corrosive agent and it is damaging to the condition of highway verges, and therefore it is crucial that a minimum of salt is spread with the most optimal result for public safety. Ireland-based spreader manufacturer Romaquip, which recently delivered a large number of Ultima spreaders to the Highways Agency, has opened up a special testing facility in which spreader performance can be measured in a scientific manner. In a WOII aircraft hangar, at the old Aston Down MOD airfield near Stroud, Romaquip has built a complete test track on which spreading performance can be measured. The company uses this facility for its own research, such as when it was developing the Ultima spreader, but external parties, such as research institutes, can also make use of this unique scientific testing facility.
It must be said that measuring spreader performance is a very time consuming process, and only two spreader tests can be executed in one day, as the chlorides have to be collected in the most meticulous manner.
At Romaquip’s facility a long stretch of tarmac has been laid, mimicking a standard UK motorway on which three sets of panels are drawn, at reasonable distance from each other. The panels are the size of each lane on motorway, and this simulated motorway also has areas that count as the hard shoulder and verges. Of course, the testing criteria can be adapted to any other type of road. When visiting the facility near Stroud in Gloucestershire. Romaquip was testing the spreading performance of its Ultima Spreader.
Technical Director of Romaquip, John McKeown explains that it is absolutely essential that the test panels on the tarmac are kept as clean as possible. ‘Even the buffer areas in between the sets of panels need to be spotless. Therefore, a truck-mounted sweeper is used to make sure there is no salt left from former tests that could contaminate the test results.
The spreader then drives over the designated test area at a speed that would be realistic on the motorway. In this case, that would be 40 miles an hour. The salt is delivered onto the road surface. What we also do is look for snaking which can happen when turbulence moves the salt where it shouldn’t be. This is another reason why the areas between the different test panels are cleaned by the sweeper,’ explains John McKeown.
Specially trained personnel carefully collect all the salt particles from each panel with a special vacuum cleaner, which not only collects the salt particles, but also washes the testing panel with a spray liquid. This liquid is then collected back into the vacuum cleaner, after which the vacuum cleaner itself is intensively cleaned of any residual salt. All possible chlorides have now been collected from the panel and the internal parts cleaning device and are poured into a plastic test container. This ensures that all chlorides are saved in to the container leaving you with a totally clean and washed panel.
He adds that it is essential that people stick to the right protocol. ‘So much money is spent on spreading performance tests that you need to have staff there that makes sure that all the vital procedures are being followed, because of the time consuming nature of the tests.’
All salt per panel in the simulated motorway are collected into containers, which are marked with each strip number and the panel number. Then the marked salt containers are taken to the support bench, where they are diluted into a standard solution volume.The solution is then fully blended to ensure that all solids are fully dissolved into the solution. This is executed by putting it into a special blender. The solution is then weighted using a very accurate digital scales and is then tested for TDS using a highly accurate and test certified meter. The results are collated into a spreadsheet and analysed to display the spread accuracy of the Ultima spreader across the test panel strips.
The salt that ends up in the verges deserves extra attention says John McKeown. ‘The percentage of salt that ends up in the left and the right hand verge, compared to what has been spread in the lanes, gives an accurate view of what has been overspread and how the vehicle has been performing. Ideally, what you are trying to do is to get a very even spread in three lanes, as well as in the hard shoulder. The spread should reach as close to the minimum and maximum width as is practically possible. Theoretically, we ideally should have no salt in the left or right hand margin, we observe the percentage in each of these margins to ensure that can reduce these percentages to the lowest values possible, as we do not want to waste any salt.’ John McKeown emphasizes that tests like the ones that are conducted in the Romaquip testing facility are becoming ever more essential for the winter maintenance industry. ‘LAs are becoming more and more accountable for winter maintenance practice, and the increasingly unpredictable weather patterns should drive them to ensure that roads are treated according to Best Practice principles, while pushing their salt costs down and protecting the environment at the same time. The main objective of our test facility is, however, to dramatically improve the current standards we have for spreading specifications in the UK.’
