w bwm08300100en GB05 - Scania North America...© Scania CV AB 2015, Sweden Cranes Crane behind cab 08:30-01 Issue 5 en-GB 3 (23) Stability is poorest when lifting obliquely in front

08:30-01 Issue 5 en-G

Cranes
General information about cranes
More information about the Machinery Directive can be found in Use and responsi-bility and in Quality and safety checks before delivery to customer.

General information about cranesThe location of the crane has a great impact on the design of the attachment. Here are some recommendations for positioning behind the cab, rear-mounted cranes and cen-trally-mounted cranes.

Cranes are subject to legal requirements in several countries. Within the EU and EF-TA, cranes are defined as machines and must follow the requirements laid out in the Machinery Directive.

B 1 (23)© Scania CV AB 2015, Sweden

CranesCrane behind cab

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Crane with articulated beam.

For more information on the front supporting legs, see Front-mounted equipment.

More information on stability calculations can be found in the document Roll stabil-ity.

Crane behind cabIn poor and very poor driving conditions, cranes with articulated beams are to be used. The driving conditions are a factor that influences the design of the beam at-tachment. If cranes with rigid beams are used under these conditions, this can cause damage to the crane attachment, chassis frame and other chassis components because the crane's attachment limits the ability of the chassis frame to flex.

For good and moderately good driving conditions, cranes with articulated and fixed beams can be used. Experience has shown that cranes with articulated beams give better comfort because the torsional flexibility of the chassis frame is not adversely affected by the attachment.

Rotate the articulated beam forwards to give a lower front axle weight and more space to operate the controls.

Always check that the crane does not overload the truck's front axle and choose tanks which give the crane's supporting legs adequate room.

StabilityThe crane's stability in use is determined by the following:

• The truck

• The load

• The supporting legs

• The ground surface

• Crane arm position in the working area

The supporting legs should be well extended for the best stability. In addition to the supporting legs, the wheels which come into contact with the ground during crane work also act as support points.

© Scania CV AB 2015, Sweden

08:30-01 Issue 5 en-GB 2 (23)


Stability is poorest when lifting obliquely in front of the truck. This can mean that the crane's lifting capacity is reduced when working in front of the truck or that the crane's operating area must be limited to an area behind the supporting legs.


08:30-01 Issue 5 en-GB 3 (23)


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AttachmentNormal crane attachmentFor good driveability, the crane should rest on special crane brackets which are screwed onto the chassis frame web.

The distance between the crane and the subframe should be 2 to 5 mm. See illustra-tion.

• Use the longitudinally flexible body adaptation brackets to fit the front section of the subframe onto the chassis frame. Crane brackets must not be used.

• Fit the crane as far forwards as possible to reduce the stresses in the chassis frame and to reduce the risk of comfort-disrupting vibrations.

More application examples can be found under the heading Subframe.

Attachment with bracesSome types of crane can be fitted using braces.

The illustration shows an example of crane brackets for braces. This type of bracket requires a lot of space and therefore cannot always be used.


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R5

45°

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304

350

Reinforced crane attachmentIn order to use larger crane sizes, the crane attachment must first be reinforced.

• Make a plate which joins the front and rear bolt attachments for the crane foot as illustrated.

• Secure the plate in the chassis frame and subframe web.

The purpose of the plate is to carry the crane.


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353403

353403

3090

1

230

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1. Rivet location on the chassis frame2. Shape of the hole in the lower flange of the subframe

SubframeA crane behind the cab gives rise to torsional forces and bending forces and high stresses at the attachment points. In order to avoid high stresses and reduce the risk of comfort-disrupting frame vibrations, the subframe should start in front of the crane and extend to the rear end of the chassis frame.

Rivets on top of chassis frameOn some vehicles, there are rivets on the top of the chassis frame that are in the way of the subframe.

• The rivet heads are 22 mm in diameter.

• Make a hole in the lower flange of the subframe to make room for the rivets. See illustration.

• The rear rivet is 353 or 403 mm (see table later in the document) behind the front axle centre.


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Bogie weight Length

Left Right

- 353 353

- No rivets 353

- No rivets 403

>=20,000 353 353

No rivets 403

- No rivets 403

On the following vehicles, there are 3 rivets on the top of the chassis frame that are in the way of the subframe.

Frame Configura-tion

Engine Gearbox Cab Front axleweight

700 - D9, D13 Manual 14 -

700 - D16 - 16 -

800 - D16 - 16 -

8x4Z D9, D13 Manual 14, 16 >=2x8,000

D16

4x2

4x4

6x2

6x2*4a

6x2*4b

6x2/2

6x2/4

6x4

6x6

950, 957, 958 8x2*6 D16 - 16 -

8x2/*4

8x2/2

8x2/4

8x4c

8x4*4d

8x4*4b


08:30-01 Issue 5 en-GB 7 (23)


Bogie weight Length

Left Right

- No rivets 403

Frame Configura-tion

Engine Gearbox Cab Front axleweight

8x4/4

8x6

950, 957, 958 8x6/4 D16 - 16 -

8x8

10x4*6

a. Right-hand drive with drum brake on the first front axleb. Left-hand drivec. Rear air suspensiond. Right-hand drive with drum brake or disc brake on the first front axle


08:30-01 Issue 5 en-GB 8 (23)


Cmax = Maximum crane size in tonne-metres

Ix = Minimum surface moment of inertia per beam in cm4

0 h x w x t = Height, width and thickness in mm

5

0 The recommendations apply to U-profile steel subframes made from a ma-terial equivalent to the chassis frame.5

More information on subframes can be found in the document Subframe design.

More information on the frame material can be found in the document Chassis frames.

Cranes dimensioned for less than 30 tonne-metres (tm)When preparing to use a tipper, fixed platform or other bodywork:

• Connect the subframe to the bodywork subframe by welding together the two sub-frame profiles.

• Select a profile dimension so that the surface moment of inertia does not fall be-low the minimum recommended value. Refer to the table.

Normal crane attachment Reinforced crane attachment

Frame Cmax

SubframeFrame Cmax

Subframe

h x w x t Ix h x w x t Ix

F800 10 110x80x6 290 F950 14-20 160x80x8 90

12 140x80x8 380 20-24 180x80x8 1,21

F950 12 110x80x6 290 F957 F958

22-26 160x80x8 90

14 140x80x8 665 26-30 180x80x8 1,21

F957 F958

22 110x80x8 380


08:30-01 Issue 5 en-GB 9 (23)


• Use crossmembers in the front section of the subframe at the crane's attachment to the chassis frame.

• On vehicles with a three-way tipper, the tipper's front support shaft should be po-sitioned as far forward as possible to avoid comfort-disrupting frame oscillations.

It is also possible to use a lower subframe for reduced total height as long as the total bending resistance of the chassis frame and subframe is not less than the recommend-ed value. Use for example a square profile subframe or stiffening plates or a complete steel plate between the subframe beams.

Note:If the subframe height (and therefore its Ix-value) varies, make sure that the transition between the different sections is as gradual as possible.


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Large cranes dimensioned for more than 30 tonne-metres (tm)Large cranes normally need 2 pairs of supporting legs and considerably more rigid and torsionally-resistant subframes.

When preparing for 2 pairs of supporting legs, the subframe must be cross-reinforced over its entire length in order to withstand the torsional forces. See illustration.


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SubframesThe examples can provide some guidance on dimensioning and design, but the body-builder is always responsible for ensuring that the strength and stability calculations have been carried out correctly.

IMPORTANT!

• Pull in the subframe beams as far as possible under the cab.

• Do not stop the subframe too sharply; instead make sure that there is a radius of at least 5 mm on the lower flange.

Large cranes on tractorsThe illustration shows an example of a design of subframe higher under the crane than under the fifth wheel. The crane is dimensioned for approximately 40-45 tm.

On the lower square profile (80x160x10 mm) there is a steel plate approximately 12 mm thick along the entire subframe. This also provides the bracket for the fifth wheel.

On top of the subframe, directly below the crane, there is an additional square profile (60x140x10 mm) and crossmembers extending as far back as the space will allow in relation to a further 12 mm thick steel plate and the connected trailer.

The stiffening plates in the example are approximately 10 mm thick.

For a crane dimensioned for approximately 50-80 tm, the stiffening plates must ex-tend down below the beam web. This allows a further square profile of approximate-ly 160x90x10 mm to be attached. An alternative is to build a box around the chassis frame connecting the front and rear pairs of supporting legs.


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Large cranes on trucksThe illustration shows an example of a design of subframe for a crane dimensioned for 45 tm.

Longitudinal square profile of 150x250x10 mm. Crossmembers with U-profiles of 220x80x9 mm and stiffening plates with a thickness of approximately 10 mm.

The same instructions as for large cranes on tractors in the previous example apply to large cranes.


08:30-01 Issue 5 en-GB 13 (23)

CranesRear-mounted crane

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Rear-mounted craneWhen loading and unloading using rear mounted cranes, the rear overhang is subject-ed to very high stresses. It is therefore important to make the rear overhang sufficient-ly rigid to avoid damage to the chassis frame and the subframe.

Rear-mounted cranes in most cases give unfavourable load conditions, as the crane is further back on the vehicle. The crane constitutes a long lever to the rearmost sup-port point on the chassis frame.

The suspension and flexing of the rear overhang which the crane causes, gives rise to corresponding movements in the chassis in front of the rear overhang and can re-sult in comfort-disrupting frame oscillations. These primarily occur on unladen ve-hicles and can seldom be completely avoided.

The front axle weight is low on an unladen vehicle with a rear-mounted crane, which can adversely affect the vehicle's steering. Use a sliding attachment so that the front axle weight can be increased when moving.


08:30-01 Issue 5 en-GB 14 (23)


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Attachment of permanently-mounted crane.

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357

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2 examples of the attachment of a permanently-mounted crane

AttachmentA rear-mounted crane can be fitted directly onto the chassis frame, with brackets in the chassis frame web.

Permanently mounted crane• Let the crane rest on the crane brackets which are screwed into the chassis frame

web.

• Adapt the number of bolts and bolt dimensions to the load.

• Reinforce the chassis frame with a subframe.

• Tie together the crane bracket, subframe and chassis frame to form a rigid unit.


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More information on screw joints is found in the Screw joints document.

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Crane attached with brackets• Attach the brackets to the chassis frame web using bolted joints.

• Adapt the number of bolts and bolt dimension to the load.

• Reinforce the chassis frame with a subframe.

• Tie together the crane bracket, subframe and chassis frame to form a rigid unit.

Attachment of crane with clampMany cranes are prepared to be attached to the subframe with a clamp. Fitting a crane with clamp is permitted if the chassis frame and subframe flanges are protected as illustrated.


08:30-01 Issue 5 en-GB 16 (23)


Cmax = Maximum crane size in tonne-metres

Lmax = Maximum distance from driving axle to frame rear end in mm

Ix = Minimum surface moment of inertia per beam in cm4

h x w x t = Height, width and thickness in mm

More information on the frame material can be found in the document Chassis frames.

SubframeSubframes for rear-mounted cranes up to approximately 20 tonne-metresU or Z-profiles are recommended to ensure that the front section of the subframe will be relatively flexible torsionally.

• Reinforce the subframe with, for example, X-rods to make it rigid in the rear over-hang.

The table below gives recommended subframe dimensions for different chassis types. It only provides examples of how to obtain the surface moment of inertia lx with a certain U-profile.

The surface moment of inertia assumes that the subframe is manufactured from steel and is of the same quality as the chassis frame.

Frame Truck model Cmax Lmax Ix h x w x t

F800

4x2 Z 82,100 690 160x80x6

3,100 1,215 180x80x8

4x2 A/B 81,600 690 160x80x6

2,600 1,215 180x80x8


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F950

4x2 Z

82,100 665 140x80x8

3,100 900 160x80x8

122,100 900 160x80x8

3,100 1,215 180x80x8

172,100 1,215 180x80x8

3,100 2,000 220x80x8

4x2 A/B

81,600 665 140x80x8

2,600 900 160x80x8

121,600 900 160x80x8

2,600 1,215 180x80x8

171,600 1,215 180x80x8

2,600 2,000 220x80x8

82,900 665 140x80x8

6x2 A/B 3,900 900 160x80x8

6x4 A/B12

2,900 900 160x80x8

8x2 A 3,900 1,215 180x80x8

8x4 A17

2,900 1,215 180x80x8

3,900 2,000 220x80x8

122,500 1,215 180x80x8

6x4 Z 3,500 1,850 210x90x8

8x4 Z17

2,500 1,350 180x90x8

3,500 2,250 230x80x8


08:30-01 Issue 5 en-GB 18 (23)


F958

122,900 665 140x80x8

3,900 900 160x80x8

6x2 Z17

2,900 900 160x80x8

8x2 Z 3,900 1,215 180x80x8

202,900 1,215 180x80x8

3,900 2,000 220x80x8

122,500 900 160x80x8

3,500 1,550 200x80x8

6x4 Z17

2,500 1,215 180x80x8

8x4 Z 3,500 1,850 210x90x8

202,500 1,350 180x90x8

3,500 2,250 230x80x8

122,900 665 140x80x8

6x2 A 3,900 900 160x80x8

6x4 A17

2,900 900 160x80x8

8x2 A 3,900 1,215 180x80x8

8x4 A20

2,900 1,215 180x80x8

3,900 2,000 220x80x8



08:30-01 Issue 5 en-GB 19 (23)


Chassis with 6x2 or 6x2*4 wheel configuration and rear axles with air suspension

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Examples of attachments

Chassis with 4x2 wheel configuration and rear axle with air suspension

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Extra reinforcement with stiffening plates.

304

351

Cross-reinforcement of the entire subframe.

Subframes for rear-mounted cranes of more than approximately 20 tonne-metresWhen preparing for large rear-mounted cranes, a normal subframe and cross-rein-forcement are not sufficient. The frame must also be reinforced with stiffening plates.

For cranes up to approximately 30 tonne-metres it is usually sufficient for the stiff-ening plates to extend from the rear edge of the frame to in front of the bogie.

For cranes of more than approximately 30 tonne-metres the stiffening plates should extend from the rear edge of the frame to level with the front pair of supporting legs.

For rear-mounted cranes which require 2 pairs of supporting legs, the entire subframe must be cross-reinforced.

Always check the front axle weight when driving an unladen truck.


08:30-01 Issue 5 en-GB 21 (23)


Max 300

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Example of closed crossmember, part number 1 426 900.

Extra crossmember for vehicles with a rear-mounted craneIn order to increase the rigidity in the chassis, Scania has designed a closed cross-member for attachment into the rear end of the chassis frame.

• Use the crossmember on chassis with air suspension or chassis with a rear-mount-ed crane.

• Attach the crossmember as far back on the chassis frame as possible. The maxi-mum distance to the rear edge of the chassis frame is 300 mm.

Proceed as follows:

• Use the holes on the end pieces as a template for drilling through the frame side members.

• Ream the holes until 14 mm in diameter.

• Fit the crossmember with 24 M14x56 tight-fit bolts and spacers.


08:30-01 Issue 5 en-GB 22 (23)

CranesCentrally mounted crane

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Further information on attachments is provided under the heading Attachment.

Centrally mounted craneWhen preparing for a centrally-mounted crane, the subframe should be the same height all along the chassis frame.

The attachment should be flexible in the front part of the subframe and rigid in the rear part.

Use rigid plates to reinforce the attachment of the subframe to the chassis frame by the crane. See illustration.

The illustration also shows an example of the design of a subframe for a British brick delivery vehicle with a centrally-mounted crane. The vehicle has an 8x4 wheel con-figuration and an axle distance of 6,500 mm.

The subframe consists of a 125x80x8 mm steel U-profile.


08:30-01 Issue 5 en-GB 23 (23)

Documents

w bwm08300100en GB05 - Scania North America...© Scania CV AB 2015, Sweden Cranes Crane behind cab 08:30-01 Issue 5 en-GB 3 (23) Stability is poorest when lifting obliquely in front