TRCTOR Using a tractor for a semi-trailer offers many opportunities to solve a variety of transport needs using the same truck. However, using the fle

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1 Contents TRCTOR... 2 COMPTIBILITY S PER ISO Manoeuvrability... 5 WHEELBSE... 7 POSITIONING FIFTH WHEEL... 8 TTCHING THE FIFTH WHEEL LOCKING FIFTH WHEEL ND MOUNTING PLTE RETROFITTING NGLE BRCKETS REINFORCING FOR 6x4 TRCTORS WITH NGLE BRCKETS SELECTING NGLE BRCKET OR UXILIRY FRME NGLE BRCKETS UXILIRY FRME TYPES OF FIFTH WHEEL " kingpin " kingpin Universally jointed Replaceable locking mechanism Moveable Raisable and lowerable fifth wheel FCTORY FITTED FIFTH WHEELS FROM SCNI Calculating the D-value for tractors with semi-trailers Factory fitted angle brackets for different types of chassis Factory fitted moveable fifth wheels Scania CV

2 TRCTOR Using a tractor for a semi-trailer offers many opportunities to solve a variety of transport needs using the same truck. However, using the flexibility of a tractor means that international and national legislation and standards must be complied with, when selecting the wheelbase and positioning the fifth wheel. Before coupling the tractor and semi-trailer, always check that they are built to the same standard Scania CV 2002

3 COMPTIBILITY S PER ISO 1726 ISO 1726 is an international standard covering characteristics and location of the fifth wheel, and the space that must be available for the semi-trailer. Technically, tractors and semi-trailers that comply with this standard can be combined. In addition to technical compatibility, regard must be taken to regulations concerning external dimensions and axle loads of the vehicle combinations. ccording to the international ISO standard, the height of the fifth wheel () on a loaded tractor should be: =min 1150 mm = max 1300 mm Fifth wheel height () for tractor without semitrailer. = max 1400 mm Bulk goods tractor adapted for 2.9 m high container as per ISO. Laden tractor. = min 1025 mm = max 1100 mm 1 2 Unladen. = max 1150 mm ß1 ß2 The limit for fifth wheel movement longitudinally and laterally should be: upwards: min 8 ( b1 ) downwards: min 8 ( b2 ) laterally: max 3 ( a1 = a2 ) 26:4120 Scania CV

4 In order to ensure adequate clearance between tractor and semi-trailer in all driving conditions, the tractor must permit a slope angle for the semi-trailer of at least: forwards: 6 ( w1 ) rearward: 7 ( w2 ) w1 w2 26:4126 NOTE: ISO ( w2 ) gives clearance above tyres with no consideration taken for any mud guards. 4 Scania CV 2002

5 Manoeuvrability In order for the tractor to be freely manoeuvred, the diagonal front overhang of the semi-trailer (front swept radius D) must not exceed 2040 mm. (This figure corresponds to a front overhang of 1600 mm from the kingpin to the front edge of the semi-trailer with a trailer width of 2500 mm.) The rear part of the tractor must also have requisite clearance. Minimum distance between kingpin and semi-trailer landing legs is designated G. n additional clearance of 100 mm is recommended between radii J and G, to allow for the necessary angular differences between the tractor and semi-trailer. Check this dimension at an operating angle of 90. D J G J = max 1940 mm D = max 2040 mm G = max 2300 mm 26:4111 In order to ensure that the semi-trailer has sufficient clearance in relation to the tractor, a hitch profile can be drawn up, giving essential dimensions. This profile is often called a swan-neck profile and permits interchangeability between all tractors and semi-trailers built according to the ISO standard. Values matched to these dimensions are as follows: S Y R S = min 750 mm Y = max4 R = max 450 mm G = min 2300 mm G 26:4110 Scania CV

6 In order to be able to haul a 13.6 m trailer (EU trailer) within a total length of 16.5 m, the distance between the front of the tractor and the centre of the fifth wheel should be no more than 4500 mm. 26:4130 Max 4500 mm This is a short introduction to ISO For further details concerning this international standard or local standards please contact the appropriate national standards organisation. 6 Scania CV 2002

7 WHEELBSE The choice of wheelbase is affected by factors such as the front overhang on the semi-trailer and regulations that govern the total vehicle length and the gross vehicle weight. This limits the choice of where to place the fifth wheel lengthways. However, technically the following general rules apply: truck with a long wheelbase is more susceptible to chassis frame vibration. Since the distance between the chassis frame support points (the front axle and the rear axle) is large, the natural frequency of the chassis frame will be low. First and foremost a chassis designed for tractors, an chassis, should be specified. Otherwise: Select the shortest possible wheelbase. The wheelbase measurements to the right are primarily recommended for fifth wheel installation. Chassis type PR 4x2 PR 6x2 B PR 6x2 Z PR 6x2/4 PR 6x4 T 4x2 T 6x2, 6x4 Wheelbase (mm) 3300, 3550, , , 3300, , , 4300 Scania CV

8 POSITIONING FIFTH WHEEL In addition to that mentioned in the previous paragraph, there are several factors which affect the position of the fifth wheel. The semi-trailer must not strike the cab or the rear of the chassis frame, but handling must be good. In order to utilise the maximum load-carrying capacity of the front axle, the fifth wheel is usually located far forward on long trucks, which increases susceptibility to chassis frame vibration. If the fifth wheel is positioned centrally over the rear axle or over the theoretical bogie centre, this effect is decreased. On the other hand, steering is made less sensitive and the driver has poor control of the semi-trailer. n intermediate position should be selected, providing both good handling and acceptable axle load distribution. If the distance between the fifth wheel and the rear axle section is large, the semi-trailer will endeavour to displace the truck laterally when the semitrailer heels over (when cornering or skidding). This may be dangerous on a slippery road surface. This effect varies with load and road conditions and depends on the magnitude of acceleration or retardation. It is not possible to give precise recommendations for positioning the fifth wheel that take into consideration all factors, e.g. chassis type, wheelbase, chassis equipment, required axle loads and legal requirements. When deciding the location of the fifth wheel, always check the axle loads in each individual case. lways check that the space between the semi-trailer and the rear edge of the chassis frame is sufficient. 8 Scania CV 2002

9 The following instructions give general guidelines for fifth wheel location. Experience shows that the vehicle unit will handle well when: - The fifth wheel of a two-axle tractor is located at a distance of 10% of the wheelbase forward of the rear axle. - The fifth wheel of a three-axle tractor is located at a distance of 10% of the wheelbase forward of the theoretical bogie centre. The theoretical bogie centre is shown on the main dimension drawings. This positioning gives relatively low front axle load, which can be increased by positioning the fifth wheel somewhat further forward. If the fifth wheel is moved too far forward, more than 700 mm ahead of the driving axle on two-axle vehicles, handling will be impaired and the risk of exceeding the permitted front axle weight is increased. On 6x2/4 vehicles the fifth wheel is more than 700 mm ahead of the driving axle and handling is impaired when driving with the tag axle raised, which could be considered an unfavourable characteristic. On chassis with a T cab which have a longer wheelbase it may instead be difficult to position the fifth wheel far enough to the rear without exceeding the maximum permitted rig length. Fifth wheel mounting places a highly concentrated load on the chassis frame. From the loading aspect the fifth wheel should therefore be positioned no further than 600 mm ahead of the rear axle on a two-axle tractor. n exception to this are chassis that are adapted to the tractor ex works and on which the fifth wheel can be mounted in a pre-drilled position a maximum of 760 mm ahead of the rear axle. B = max. 600 mm (from the factory 760 mm) In order to comply with EU directives concerning tractor combinations, the distance between the front of the tractor and the centre of the fifth wheel should not exceed 4500 mm, see also page 6. The fifth wheel on tractors with a plastic bumper should then be mounted as indicated in the table below. Tractors with a steel bumper are 35 mm longer, so the fifth wheel must also be positioned 35 mm further forward. B = 260 mm for wheelbase x2 510 mm x2 660 mm x2 935 mm x2 / mm x2 /4 = 140 mm x2 On three-axle tractors, the fifth wheel is located as set out in in the diagram = min 90 mm 6x2, 6x4/B 100 mm 6x4Z B 26: :4101 Scania CV

10 TTCHING THE FIFTH WHEEL The fifth wheel should be attached to a mounting plate. The mounting plate provides a suitable attachment for the fifth wheel against the angle brackets or auxiliary frame. suitable design of mounting plate is shown in the adjacent figure. 40 r r20 26: One of the mounting plates in the adjacent figures can be used on trucks that require particularly low fifth wheel heights, In order to avoid the mounting plate being bent down, the cross members underneath should be used. max 100 If low angle brackets are used, the end surfaces on the mounting plate must not chafe the chassis frame. This may cause damage to the chassis frame. min r min The end surfaces of the mounting plate should therefore be bent up as shown in figures. The mounting plate should be designed so that the contact pressure on the auxiliary frame is distributed evenly onto at least four support surfaces. 26: To avoid damage to the chassis frame, the end surfaces of the mounting plate must be rounded or bent up. Moveable fifth wheel bridge-piece should be secured in accordance with the manufacturer s instructions. 10 Scania CV 2002

11 LOCKING FIFTH WHEEL ND MOUNTING PLTE t the factory fifth wheels are mounted on the mounting plate using special bolts dacroment, tightened to a specific torque. If the fifth wheel is loosened from the mounting plate new M bolts and welded stops should be fitted. The mounting plate is mounted on the angle brackets using four M18 and four M20 tight-fit bolts. NOTE the mounting plate for 3.5" fifth wheels is mounted using eight M20 tight-fit bolts + four welded stops. 26:4122 NOTE the mounting plate for 3.5" fifth wheels is attached as set out above. RETROFITTING NGLE BRCKETS ngle brackets should be attached to the webs of the chassis frame using rivets or bolted joints. The number of bolts depends on the length of the angle bracket. s a rule, it is necessary to use at least 10 bolts. Use M14 bolts. When retrofitting we recommend that the fifth wheel is secured on the mounting plate by welded stops and the mounting plate is secured to the chassis by using either four M18 and four tight-fit bolts or eight M18 bolts and welded stops. If angle brackets higher than 40 mm are fitted, cross members should be used between the angle brackets in order to distribute lateral forces from the semi-trailer. On 4x2, the angle brackets may not be above the chassis frame, as the shape of the angle bracket makes it too weak to carry the load from the fifth wheel on its own. Scania CV

12 REINFORCING FOR 6x4 TRCTORS WITH NGLE BRCKETS When driving on winding roads with high bogie loads, it may sometimes be necessary to provide reinforcement with a cross as illustrated, in order to prevent damage to "cross" members or retroactively if damage has occurred to cross members. Steel rod 70 x 10 mm. M16 tight-fit bolts Do not weld the cross, only use straps to eliminate noise. 12 Scania CV 2002

13 SELECTING NGLE BRCKET OR UXILIRY FRME This choice is made based on the semi-trailer load on the chassis, the chassi-class and the driving conditions. NGLE BRCKETS The angle bracket is standard on chassis designed for tractors and is suitable for long-distance driving and normal gross weights with a D value of up to 152 kn. For heavier loads with 6x4Z and bogie BT300B, a fifth wheel with 3.5" kingpin, sturdier angle brackets and mounting plate is available. Having a D value of 260 kn it is recommended for gross train weights of up to 70 tonnes on bad roads and 120 tonnes on good roads. If higher gross train weights are required, an auxiliary frame is recommended. UXILIRY FRME We recommend an auxiliary frame when Scania s angle bracket cannot be used. The auxiliary frame distributes the point load applied by the fifth wheel and reinforces the chassis frame. The auxiliary frame raises the fifth wheel, which is often necessary to safeguard adequate clearance between the semi-trailer and the wheels and/or the rear ends of the chassis. NGLE BRCKET uxiliary frame example for F958 frame. Section type Height x width x thickness (mm) UXILIRY FRME Min. surface moment of inertia per member 4 l (cm ) X U 110x80x8 380 Z 110x80x80x8 380 The dimensions of the auxiliary frame are dependent on the load, operating conditions and the space required. s a general rule, it is advisable to use auxiliary frame dimensions with a minimum surface moment of inertia as in the table opposite, when kingpin loads are high or operating conditions difficult. For more general information about auxiliary frame, see Chapter 2. The auxiliary frame should consist of open Z or U sections. Scania CV

14 Lateral forces from the trailer when cornering should be distributed between the chassis frame members. If lateral forces are applied to one frame member only, this may become twisted and bent. For this reason, the auxiliary frame should be fitted with cross members in front of and behind the fifth wheel mounting points. For heavy transport with high a total vehicle weight, the auxiliary frame should be provided with several thick cross members forward of and behind the fifth wheel mounting points Cross members should be used forward of and behind the fifth wheel mounting points. Example of auxiliary frame for fifth wheel mounting. 14 Scania CV 2002

15 26:4105 Heavy tractor Scania CV

16 The length of the front part of the auxiliary frame can be significant in preventing chassis frame vibration. n auxiliary frame which extends far forwards makes the chassis frame rigid at this point. The natural frequency of the chassis is raised, which generally means that vibration occurs at road speeds higher than those at which the truck is normally driven. Whether or not the auxiliary frame should be extended forwards must be determined from case to case. s the wheelbase increases, it is more necessary to extend the auxiliary frame forwards. 26:4100 If the auxiliary frame is extended forwards as shown by the dashed line in the illustration, the front section of the auxiliary frame should be bent outwards so that it follows the chassis frame. 16 Scania CV 2002

17 TYPES OF FIFTH WHEEL Different types of fifth wheel with special characteristics are available to suit a variety of haulage tasks. 2" kingpin The standard type of fifth wheel has a 2" diameter kingpin and is usually rubber-mounted to allow a certain amount of angling. The 2" diameter kingpin is used for kingpin loads up to 20 tonnes. 3.5" kingpin fifth wheel with a 3.5" kingpin is usually employed for kingpin loads in excess of 20 tonnes and is mainly intended for heavy special transport. Universally jointed universally jointed fifth wheel is often fitted if the vehicle is used under difficult conditions, with large angular differential movement between tractor and semi-trailer. This type of fifth wheel allows for large angular movement both laterally and longitudinally. universally jointed fifth wheel normally has a kingpin diameter of 3.5". Scania CV

18 Replaceable locking mechanism fifth wheel with a replaceable locking mechanism can accommodate both 2" and 3.5" kingpins to meet different transport requirements. Moveable moveable fifth wheel can be fitted, for maximum utilisation of the tractor, particularly in international haulage work. moveable fifth wheel enables the rig to be adjusted to suit various national regulations concerning axle loads and vehicle lengths. It also allows improved weight distribution between the front and rear axles, and enables adaptation to different types of semi-trailer. 26:4109 Raisable and lowerable fifth wheel raisable and lowerable fifth wheel makes it possible to use a low construction tractor, even with conventional trailers. 26: Scania CV 2002

19 FCTORY FITTED FIFTH WHEELS FROM SCNI Fixed fifth wheels: Manufacturer Model Material D- value U- value kn kg VBG 2" VBG 150SP 148 pressed steel GF 2" SK-S cast iron GF 2" SK-S36.20 W 150 cast iron Jost 2" JSK 37 C W 150 cast iron Jost 2" JSK 37 C Z 150 cast iron GF 2" SK cast iron GF 2" SK W 185 cast iron Jost 2" JSK 37 C Z 185 cast iron Jost 2" JSK 37 C W 185 cast iron Jost 2" JSK 37E 185 cast iron Jost 2" JSK 36DV17G 205 pressed steel VBG 2" VBG 150SP 210 pressed steel BigD 2" YF pressed steel Jost 2" JSK 37 C Z 250 cast iron Jost 3.5" JSK 38 C-1 3.5/190 cast iron Jost 3.5" JSK 38 G-1 3.5/290 cast iron D-value = theoretical horizontal force U-value = max vertical imposed load Fixed fifth wheels with mounting plates 22 and 40 mm Manufacturer Model D- value U- value With 22 mm With 40 mm mounting plate mounting plate kn kg Height Weight Height Weight VBG 2" VBG 150SP GF 2" SK-S GF 2" SK-S36.20 W Jost 2" JSK 37 C W Jost 2" JSK 37 C Z GF 2" SK GF 2" SK W Jost 2" JSK 37 C Z Jost 2" JSK 37 C W Jost 2" JSK 37E Jost 2" JSK 36DV17G VBG 2" VBG 150SP BigD 2" YF Jost 2" JSK 37 C Z Jost 3.5" JSK 38 C Jost 3.5" JSK 38 G Sliding fifth wheels: Manufacturer Model Height Material D- value U- value Weight Sliding distance mm kn Kg Kg step total Jost EVDM Pressat stål x Jost EVDVM Pressat stål x VBG (not 4x2) VBG 135SF 245 Pressat stål x BigD YF Pressat stål x Jost EVDVM Pressat stål x VBG (only 4x2) VBG 135SF 265 Pressat stål x Scania CV

20 Calculating the D-value for tractors with semi-trailers D = g x 0,6 x T x R ( kn ) T + R - U U 26:4148 T R T = Technically permitted overall weight in tonnes for the tractor. R = Technically permitted overall weight in tonnes for the semi-trailer. U =Vertical load in tonnes on the fifth wheel. g = 9,81 m/ s 2 20 Scania CV 2002

21 Factory fitted angle brackets for different types of chassis 95 26:4134 4x2 /B 95 26:4138 4x2/4x4 Z Factory-fitted angle brackets on two-axle tractors are level with the chassis frame. On three-axle tractors they are mounted so that they protrude 40 mm above the chassis frame :4136 6x2/6x4 /B Scania CV

22 40 26:4137 6x2/4 /B 40 F F950 26:4139 6x2 Z 40 26:4140 6x4 Z 22 Scania CV 2002

23 Factory fitted moveable fifth wheels = Moveable range :4141 4x2 and 4x4 with Jost EVDVM 2-10 = 585 mm 6x4Z BT201 6x4 /B 6x2/B/Z x2 and 6x4 with Jost EVDVM 2-10 = 585 mm Scania CV

24 = Moveable range. 728 d d d 3700, x2 and 4x4 with Jost EVDVM = 468 mm x2/4 303 with Jost EVDVM 1-01 = 468 mm x4/B 82 6x2/B 30 6x2 /B and 6x4 /B 303 with Jost EVDVM 1-01 = 468 mm Scania CV 2002

25 635 d d 3550, 3700 = Moveable range x2 and 4x4 with VBG 135 SF 4146 = 525 mm 1160 d d x2/ with VBG 135 SF = 525 mm :4148 6x2 /B and 6x4 /B with VBG 135 SF = 525 mm Scania CV

26 = Moveable range. 635 d d 3550, 3700, x2 and 4x4 260 with BigD YF 201 = 450 mm d d x2/4 300 with BigD YF 201 = 450 mm x2 /B and 6x4 /B with BigD YF = 450 mm 26 Scania CV 2002

27 762 = Moveable range x2 and 4x with Jost EVDM = 660 mm x2/ with Jost EVDM = 660 mm x2 /B and 6x4 /B 4154 with Jost EVDM = 660 mm Scania CV

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