1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140 
Which way to weigh ?
Page 37
If you've noticed an error in this article please click here to report it so we can fix it.
Demonstration for CM reveals worrying directional variations
by CM reporter DIFFERENCES 'in printed-out axle weights produced by dynamic electronic weighing equipment according to the direction of travel of the vehicle must give rise to serious misgivings about operators being prosecuted, and perhaps convicted, on ,evidence of this nature.
At The RHA tipper convention in Harrogate last weekend, CM was given an exclusive demonstration of the Weighwrite ADS electronic weighing equipment on which the vehicle concerned, an eight-wheel DAF tipper, was weighed forward and in reverse in two directions.
This equipment is currently being evaluated by the DoE for use at roadside checks by both DoE and trading standards examiners. The print-out which resulted from the demonstration, reproduced here, showed that 'significant discrepancies could arise in the stated weight of the same axle according to the direction in which the vehicle was travelling.
For instance, in weighing the vehicle in forward gear in one direction, the second axle showed 6.07 tonnes, or 0.07 tonnes (70kg) overweight. Approaching from the opposite direction, still in forward gear, the 'axle weighed 5.96 tonnes, or 0.04 'tonnes (40kg) under the permitted weight.
In imperial terms, the difference between the two weights was about 21cwt. At liowt exicess, the first weighing was enough to earn the operator et least a caution, though the second weighing would have shown the axle to have been almost lcwt under the limit.
I asked Mr B. W. Brudenell, deputy trading standards officer for Surrey, who was standing nearby with a senior DoE official, if he thought this did not react unfairly against the operator.
He told me that a trading standards officer had not the power to require a vehicle to be weighed twice. However, there was no reason why a dissatisfied driver could not ask to be allowed to put his vehicle over the equipment in the opposite direction if he was not satisfied.
It became apparent that a driver Who made such a request would have little chance of getting agreement, for as Mr Brudenell pointed out, such checks are usually held in lay-bys. Vehicles would normally enter 'at one end and leave at the opposite end. To turn a vehicle and drive it against the traffic flow would cause chaos.
The DOE official pointed out that. though the Road Traffic Act 1974 gave powers for regulations 'to be made to allow the use of electronic -weighing equipment, no such regulation's had yet been made. For some years, the DoE had been cooperating with manufacturers to try to get a machine that would weigh on the move so that weighings could be speeded up and yet provide an accurate weight record.
The Department was fully aware that discrepancies could arise, and that was one of the reasons why the development of the equipment was taking so long. However, it was possible that when regulations were made they would take into account any differences Which might arise in weighing because of the application of opposing forces.
Mr IL F. Gorman, managing director of Weighwrite, suggested that 'in turning the vehicle round there could be a transference of load from one axle to 'another. Conceding this point, it was obvious that this had not happened in the case under discussion because such a weight 'transference would show up in weighing the other axles. This had not 'happened.
Mr Gorman said that the discrepancies arose through the direction of forces reacting on the 'load cells in the weighing platforIn. There was also the variation in the reaction of the vehicle suspension to take into account.
The figures shown here ar actual print-out from the V write during the test. We added the letters ABCD to in the four axles. The bottor shows the first forward wei the next set the first ri weighing, the next highest of the second reverse we and the top set is of the s weighing in a forward din The discrepancy in gvw (arri by automatic totalling of till weights) is also notable.