PERFORMANCE OF ARTICULATED VEHICLES AND ROAD TRAINS REGARDING ROAD DAMAGE AND LOAD CAPACITY Klaus-­‐Peter Glaeser Federal Highway Research InsFtute (BASt) Germany Besides safety performance, economic performance and environmental performance the road wear performance of trucks and truck combinaFon plays a major role for road authoriFes and administrators. The society has to pay for the ruTng damage caused by truck traffic. COST 334 Tyre ConfiguraFon Factor: •  The TCF value relates the pavement wear of a given tyre to the pavement wear of a reference tyre. Within different axle categories (steered, driven or towed axle) there is a wide range of TCF values which reflects the fact that there are more and less pavement damaging tyres and tyre configuraFons as opFons possible. •  Tyre assembly (single/dual), tyre width and tyre diameter are the most important factors which influences the TCF. COST 334 Axle Wear Factor: •  The damage contribuFon of a single passage of an axle is expressed by the so called axle wear factor (AWF). This AWF is a dimensionless factor relaFng the damage contribuFon of a specific tyre at a given axle load to the damage contribuFon of a single passage of the reference tyre(s) with a reference axle load. Reference for the AWF means a passage of a 10 t axle equipped with 295/80R22,5 tyres mounted as twin assembly. COST 334 Load Equivalency Factor: To adjust the axle load effect on pavement damage a load equivalency factor (LEF) was introduced by COST 334. If only asphalt roads in the primary road network are considered and only primary ruTng as damage cause is taken into account the pavement damage increases with the power of 2 by axle load. (No ruTng on concrete roads!) COST 334 Vehicle Wear Factor: •  The sum of all axle wear factors is called vehicle wear factor (VWF). For equal TCF and LEF the higher the number of axles the higher is the vehicle wear factor, but on the other hand the higher the payload can be. •  For the same gross vehicle weight the higher the number of axles the lower is the axle wear factor for each axle and also the vehicle wear factor as sum of all axles. COST 334 Vehicle Wear Performance: The performance of a vehicle regarding pavement wear can be calculated by relaFng the payload to the vehicle wear factor. This performance indicator: “VWF / Payload” is abbreviated in the following as PER (vehicle road wear performance). Formulas Used: •  Load Equivalence Factor: LEF= (axle load / 10)² •  Tyre ConfiguraFon Factor: (tyre width/470) -­‐1,65 x (tyre diameter /1059) -­‐1,12 •  Calculated Tyre ConfiguraFon Factors: TCF: see Table 4.67 in the COST 334 Report •  Axle Wear Factor: AWF=TCF x LEF •  Vehicle Wear Factor: VWF=SUM (AWF) •  Vehicle Road Wear Performance: PER: VWF / Payload Differences in Tyres and Axle ConfiuguraFons •  Steering Axle: –  Europe + Australia: 295/80 or 315/80 (rare 385/65), volume transp. : 315/60 or 315/70 –  US + Canada: 295/75 –  SA: 315/80 or 385/65 –  Mex: 11‘ •  Drive Axle: –  All twins, no super singles, Sizes: see steering axles •  Towed Axles: –  Europe: Singles 385/65, only volume transp.: 275/70 as duals –  All other: Duals: SA: 12‘, US: 295/75, AUS: 11‘, The OECD/JTRC Study •  From the members of the OECD working group vehicle data such as gross vehicle weight (GVW), payload, axle loads for 39 arFculated vehicles were provided and the data on tyre size and tyre assembly (single/dual) as well. •  The truck combinaFons were divided in 21 “workhorse vehicles”, 13 “higher capacity vehicles” up to 50 t GVW and 25 m length and 5 “very high capacity vehicles” (road trains) with a length over 30 m and GVW>50t. Example Vehicle: EUROPE 2 Vehicle classificaFon: Workhorse vehicle Payload (t): 26.0 Total cargo volume (m3): 87.6 Example: Ref. Vehicle: EUROPE 2 Tyres
295/80R22,5 295/80R22,5 385/65R22,5 385/65R22,5 385/65R22,5
Dual/Single
S
D
S
S
S
Axle Load (t)
6,5
11,5
7,33
7,33
7,33
AWF
1,33
1,32
1,21
1,21
1,21
VWF
6,28
PER
: 26 = 0,24
African and Australian Workhorses Vehicle origin
& identification
number
GCM (t) /
Payload (t)
Length (m)
Schematic
Vehicle description
& vehicle code
AFRICA
South Africa 1
ZA1-w
43.50
28.14
15.31
Tractor semi-trailer
T12b3
South Africa 2
ZA2-w
49.30
31.90
17.75
Tractor semi-trailer
T12b3
AUSTRALIA
Australia1
AU1-w
45.50
29.00
19.00
Tractor semi-trailer
T12b3
American Workhorses AMERICA
21.55 m
Tractor semitrailer
T12b2
21.55 m
Tractor semitrailer
T12b3
20.80 m
Tractor semitrailer
T12b2
20.80 m
Tractor semitrailer
T12b3
21.56 m
Tractor semitrailer
T12b2
Canada 1
CA1-w
39.50 t
25.30 t
Canada 2
CA2-w
46.50 t
31.30 t
Mexico 1
MX1-w
44.00 t
28.65 t
Mexico 2
MX2-w
48.50 t
32.35 t
Mexico 3
MX3-w
44.00 t
28.65 t
United States 1
US1-w
36.35 t
21.15 t
19.77 m
United States 2
US2-w
36.36 t
23.46 t
21.98 m
United States 3
US3-w
41.90 t
26.70 t
19.77 m
Tractor semitrailer
T12b2
B-double
T11b2b1
Tractor semitrailer
T12b3
European Workhorses Belgium 1
BE1-w
39.00 t
25.00 t
16.20 m
Tractor semi-trailer
T11b2
Denmark 1
DK1-w
44.00 t
30.00 t
16.48 m
Tractor semi-trailer
T11b3
Denmark 2
DK2-w
48.00 t
32.00 t
18.75 m
Rigid truck trailer
R12a1b2
Denmark 3
DK3-w
48.00 t
32.30 t
16.50 m
Tractor semi-trailer
T12b3
Europe 1
EU1-w
38.00 t
24.00 t
16.50 m
Tractor semi-trailer
T11b2
Europe 2
EU2-w
40.00 t
26.00 t
16.48 m
Tractor semi-trailer
T11b3
Europe 3
EU3-w
40.00 t
27.00 t
16.90 m
Truck trailer
R11a1b2
Europe 4
EU4-w
40.00 t
25.00 t
18.75 m
Rigid truck with rigid
drawbar trailer
R12a2
44.00 t
29.10 t
16.50 m
Tractor semi-trailer
T12b3
44.00 t
28.00 t
16.50 m
Tractor semi-trailer
T12b3
United
Kingdom 1
UK1-w
United
Kingdom 2
UK1-w
Results Workhorses EU2=Ref. (overloaded?) 4 axle Tractor-­‐Semitrailer (39t GVW) with 9t axle load on single tyres (steer and towed) and 12t on drive axle with twins (allowed 11,5t max!) Higher Capacity Vehicles Vehicle origin &
identification
number
GCM (t) /
Payload (t)
Length (m)
Schematic
Vehicle description
& vehicle code
AFRICA
South Africa 3
ZA3-h
56.00
33.80
21.97
B-double
T12b3b2
South Africa 4
ZA4-h
56.00
34.24
21.98
B-double
T12b2b2
AMERICA
Canada 3
CA3-h
62.50
42.30
20.43
B-double
T12b3b2
United States 4
US4-h
36.36
23.58
22.06
‘A’ train double
T11b1a1b1
United States 5
US5-h
44.10
28.90
25.12
Tractor semi-trailer
T12b3
AUSTRALIA
Australia 2
AU2-h
68.00
44.50
25.01
B-double
T12b3b3
European Higher Capacity Vehicles GCM (t) /
Vehicle
Payload
origin &
identification
(t)
number
Length
(m)
60.00
39.30
Denmark 4
DK4-h
60.00
40.70
25.25
Denmark 5
DK5-h
60.00
38.00
25.10
40.00
25.00
Netherlands 1
NL1-h
50.00
33.41
Netherlands 2
NL2-h
Netherlands 3
NL3-h
Schematic
Vehicle description
& vehicle code
EUROPE
Belgium 2
BE2-h
Germany 1
D1-h
Vehicle
Classification
25.25
25.23
European
modular
vehicle
European
modular
vehicle
European
modular
vehicle
European
modular
vehicle
Tractor semi-trailer
with rigid drawbar
trailer
T12b3a2
Truck trailer
R12a2b3
B-double
T12b2b3
Tractor semi-trailer
with rigid drawbar
trailer
T11b3a2
24.20
Higher
capacity
Rigid truck with two
rigid drawbar trailers
R11a2a2
60.00
37.70
25.25
European
modular
vehicle
Tractor semi-trailer
with rigid drawbar
trailer
T11b3a2
60.00
39.72
25.24
Higher
capacity
Rigid truck trailer
R12a2b3
Road Wear Performance of Higher Capacity Vehicles Volume Capacity Related Vehicles
Very High Capacity Vehicles Vehicle
origin &
identifycation
number
GCM (t) /
Length (m)
Payload (t)
Schematic
Vehicle
descripttion &
vehicle code
AMERICA
Canada 4
CA4-v
62.500
37.300
38.330
A’ train double
T12b2a2b2
Mexico 4
MX4-v
66.500
42.849
39.080
‘A’ train double
T12b2a2b2
United
States 6
US6-v
53.752
37.287
31.570
‘A’ train triple
T11b1a1b1a1b1
United
States 7
US7-v
57.040
32.840
30.960
‘A’ train double
T12b2a2b2
AUSTRALIA
Australia 3
AU3-v
90.500
60.000
33.310
B-triple
T12b3b3b3
Road Wear Performance of Very High Capacity Vehicles Density of Goods •  In the disFncFon of payload capacity and volume capacity the determinant factor is the specific weight or the so called “density” of the load to be transported. •  The example truck “Europe 2” above, has 26 t payload capacity and 87.6 m³ volume capacity. This means the cargo may have a density 0.3 kg/
dm³ or less to avoid overloading. (Empty beer botles in boxes have just the density of 0.3 kg/dm³). Examples of the specific gravity for different goods [Kg/dm³ = t /m³] Water, Milk, Beer, etc. 1 kg / dm³ Fuel, Oil, Ethanol, etc. 0,6 -­‐ 0,8 kg /dm³ Earth and Soil 1,3 -­‐ 2,0 Kg / dm³ Concrete 2,2 kg / dm³ Bricks 1,9 kg / dm³ Alloy 2,7 kg / dm³ Steel 7,9 kg / dm³ Wood (dry) 0,5 -­‐ 0,9 kg / dm³ Rubber 1,2 kg / dm³ Beer boxes with 20 empty botles (0,3mx0,3mx0,4m ) weigh 10 kg: 0,3 kg /dm³ Beer boxes with 20 filled botles (same size, but 20 kg):
0,6 kg / dm³ Refrigerators (white goods) 0,14 kg / dm³ Nine passenger cars,1,5 t each, on a 100m³ transporter :
0,135 kg / dm³ Single dispatched items (parcels) 0,15 kg/ dm³ Styropor 0,04 kg / dm³
GVW „Europe2“ by WIM in Germany Load Efficiency (Payload/ GVW) of HGV by ConFnents The differences between workhorse and high or very high capacity vehicles are small. The payload share on the GVW is in almost all cases between 60% and 70%. Final Remark This presentation deals only with the performance
of different truck units on pavement wear.
The performance concerning bridge loads or turning
ability and other impacts on infrastructure are not
examined.
The topography and the existing road network in
different countries and regions in the world plays a
major role in defining maximum weights or
dimensions for heavy goods vehicles.