BOSSCO Ladderspan 3T User manual

LADDERSPAN 3T
Mobile Aluminium Tower
1450/850 Ladderspan
3T - Through the Trapdoor Method
USER GUIDE

BoSS Ladderspan User Guide
1
Please read this user guide carefully. Please note that diagrams
are for illustrative purposes only. User guides are also available
to download from our website at bossaccesstowers.com/uk/
resources/literature.
BoSS mobile aluminium towers are light-weight scaffold towers used
throughout the building and construction industry for both indoor
and outdoor access solutions where a stable and secure platform is
required. Ideal for maintenance and installation work or short-term
access, the highly versatile towers provide a strong working platform
for a variety of heights.
This user guide provides you with step by step instructions to ensure
your system is assembled easily and safely, using the 3T (Through
the Trapdoor) method.
The law requires that personnel erecting, dismantling or altering
towers must be competent. Any person erecting a BoSS mobile tower
must have a copy of this guide. For further information on the use
of mobile access and working towers consult the PASMA operators‘
code of practice.
If you need further information, design advice, additional guides
or any other help with this product, please contact the manufacturer
on [phone] or email [email protected]
Safety First
INTRODUCTION
COMPLIANCES
The BoSS Ladderspan aluminium system has been tested and
certied to EN 1004: 2004 Class 3
Instruction Manual EN 1298-IM-EN
PREPARATION AND INSPECTION
Inspect the equipment before use to ensure that it is not damaged
and that it functions properly. Damaged or incorrect components
should not be used.
Mobile Towers - 3T Method

2
bossaccesstowers.com
Safety First
SAFE USE
LIFTING OF EQUIPMENT
●Tower components should be lifted using a reliable lifting material
(e.g. strong rope), employing a reliable knot (e.g. clove hitch), to
ensure safe fastening and always lift within the footprint of the
tower.
●Assembled mobile towers should not be lifted with a crane or
other lifting devices.
● Check that all components are on site, undamaged and that
they are functioning correctly - (refer to Checklist and Quantity
Schedules). Damaged or incorrect components should not be
used.
● Check if the ground on which the mobile access tower is to be
erected and moved is capable of supporting the tower.
● The safe working load is 275 kgs (606lbs), per platform level,
uniformly distributed up to a maximum of 950kgs (2100lbs),
per tower (including self-weight).
●Towers must always be climbed from the inside using the built-
in ladder during assembly and use.
●It is recommended that towers should be tied to a solid
structure when left unattended.
●Adjustable legs should only be used for levelling.

BoSS Ladderspan User Guide3
Safety First
STABILISERS/BALLAST
● Stabilisers or outriggers and ballast weights shall always be tted
when specied.
● The Quantity Schedules show the recommended stabilisation.
In circumstances where there is restricted ground clearance for
stabilisers/outriggers, contact your supplier for advice. Ballast
must be of solid materials (i.e. not water or loose sand) and should
not be positioned to overload individual legs. Ballast should be
secured against accidental removal where practicable, and be
supported on the lowest rung of the bottom frame.
MOVEMENT
●The tower should only be moved by manual effort, and only from
the base.
●When moving the tower, beware of live electrical apparatus,
(particularly overhead) plus wires or moving parts of machinery.
● No person or materials should be on the tower during movement.
● Caution should be exercised when wheeling a tower over rough,
uneven or sloping ground, taking care to unlock and lock castors.
If stabilisers are tted, they should only be lifted a maximum of
25mm above the ground to clear ground obstructions.
●The overall height of the tower when being moved, should not
exceed 2.5 times the minimum base dimensions, or 4 metres
overall height.
●Before use, check that the tower is still correct and complete.
●After every movement of the tower, use a spirit level to check that
it is vertical and level and set the adjustable legs as required.
● Do not move the tower in wind speeds over 7.7 metres per second
(17mph).

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DURING USE
●Beware of high winds in exposed, gusty or medium breeze
conditions. We recommend that in wind speeds over 7.7 metres
per second (17 mph), cease working on the tower and do not
attempt to move it. If the wind becomes a strong breeze,
(expected to reach 11.3 metres per second - 25 mph) tie the tower
to a rigid structure. If the wind is likely to reach gale force, (over
18 metres per second - 40 mph) the tower should be dismantled.
WIND
DESCRIPTION
BEAUFORT
SCALE
BEAUFORT
NO
SPEED IN
MPH
SPEED IN
M/SEC
Medium Breeze
Raises dust and
loose paper, twigs
snap off
4 8-12 4-6
Strong Breeze
Large branches in
motion, telegraph
wires whistle
6 25-31 11-14
Gale Force Walking is difcult 8 39-46 17-21
●Beware of open ended buildings, which can cause a funnelling
effect.
●Do not abuse equipment. Damaged or incorrect components shall
not be used.
●Raising and lowering components, tools, and/or materials by rope
should be conducted within the lower base. Ensure that the safe
working load of the supporting decks and the tower structure is
not exceeded.
●The assembled tower is a working platform and should not be
used as a means of access or egress to other structures.
●Beware of horizontal forces (e.g. power tools) which could
generate instability. Maximum horizontal force 20kg.
●The stairway towers, featuring an inclined staircase access, are
for frequent use by personnel carrying tools and/or materials.
●Mobile towers are not designed to be suspended - please refer to
your supplier for advice.
●Do not use boxes or stepladders or other objects on the platform
to gain extra height.
Safety First

BoSS Ladderspan User Guide
5
Safety First
TIES
●Ties should be used when the tower goes beyond its safe
height, beyond the limits of the stabilisers/outriggers, or if
there is a danger of instability. They should be rigid, two-way
ties fastened to both uprights of the frame with load-bearing
right angled or swivel couplers. Only couplers suitable for the
50.8mm diameter tube of the tower should be used. Ideally,
ties should be secured to both faces of a solid structure by
means of anchorages.
●The tie frequency may vary depending on the application, but
they should (at a minimum) be at every 4 metres height.
●For further information on tying-in a tower please contact your
supplier or BoSS.
MAINTENANCE - STORAGE -
TRANSPORT
●All components and their parts should be regularly inspected
to identify damage, particularly to joints. Lost or broken
parts should be replaced, and any tubing with indentation
greater than 5mm should not be used and put to one side for
manufacture repair. Adjustable leg threads should be cleaned
and lightly lubricated to keep them free running.
●Brace claws, frame interlock clips, trapdoor latches and
platform windlocks should be regularly checked to ensure that
they lock correctly.
●Refer to the BoSS user guide for detailed inspection and
maintenance advice.
●Components should be stored with due care to prevent
damage.
●Ensure components are not damaged by excessive strapping
forces when transported.

bossaccesstowers.com 6
Safety First
Horizontal
Brace
4 Rung
Frame
Side
Toeboard
Platform
(Fixed and
Trapdoor Decks)
Diagonal
Brace
4 Rung Ladder Frame
End Toeboard
Stabiliser
2 Rung
Frame
Castor
Adjustable Leg
2 Rung Ladder Frame

BoSS Ladderspan User Guide
7
3.2
1.2
3.7
1.7
4.2 2.2
4.7
2.7
5.2 3.2
5.7 3.7
6.2 4.2
6.7 4.7
7.2 5.2
7.7 5.7
8.2 6.2
8.7 6.7
9.2 7.2
9.7 7.7
10.2
8.2
10.7
8.7
11.2
9.2
11.7
9.7
12.2 10.2
12.7 10.7
13.2 11.2
13.7 11.7
14.2 12.2
4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4
4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4
1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1
1 1 1 2 1 2 2 3 2 3 3 4 3 4 4 5 4 5 5 6 5 6
1 1 1 2 1 2 2 3 2 3 3 4 3 4 4 5 4 5 5 6 5 6
1 1 1* 2 1 1 1 2 1 1 1 2 1 1 1 2 1 1 1 2 1 1 1
1 1 1 1 2 2 2 2 3 3 3 3 4 4 4 4 5 5 5 5 6 6 6
6 6 6 6 10 10 10 10 14 14 14 14 18 18 18 18 22 22 22 22 26 26 26
2 3 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
125/150/200mm Castor Adjustable leg assembly 1450 2 Rung Ladder Frame 1450 2 Rung Span Frame 1450 3 Rung Ladder Frame 1450 3 Rung Span Frame 1450 4 Rung Ladder Frame 1450 4 Rung Span Frame 1.8m and 2.5m Fixed Deck 1.8m and 2.5m Trap Door Deck 1.8m and 2.5m Horizontal Brace (red) 2.1m and 2.7m Diagonal Brace (blue)
COMPONENT WORKING HEIGHT (m)
PLATFORM HEIGHT (m)
Quantity Schedule
1450 Width Towers
BoSS 1450 Ladderspan to EN 1004: Available in 2 lengths - 1.8m and 2.5m IMPORTANT: Please ensure you also read the Quantity Schedule on page 8. *If you are unable to position the working platform easily from the ground, you may require an additional fixed platform for this tower height.
Internal Use
Internal/External Use - Towers under 2.5m are outside of the scope of EN1004

bossaccesstowers.com 8
COMPONENT WORKING HEIGHT (m) 3.2
1.2
3.7 1.7
4.2 2.2
4.7 2.7
5.2 3.2
5.7 3.7
6.2 4.2
6.7 4.7
7.2 5.2
7.7 5.7
8.2 6.2
8.7 6.7
9.2 7.2
9.7 7.7
10.2 8.2
10.7 8.7
11.2 9.2
11.7 9.7
12.2 10.2
12.7 10.7
13.2 11.2
13.7 11.7
14.2 12.2
1.8m and 2.5m SideToeboard 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
1.2m End Toeboard 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
Toeboard Holder 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4
SP7 Fixed Stabiliser 4 4 4 4 4 4
SP10 Telescopic Stabiliser 4 4 4 4 4 4 4 4 4 4 4 4 4
SP15 Telescopic Stabiliser 4
1.8m TOWER Total Self-weight (kgs) 91 99 103 146 161 169 175 195 210 231 237 257 272 279 300 306 320 328 334 354 369 377 383
2.5m 108 116 143 169 185 194 201 226 243 264 271 296 313 321 343 354 370 378 385 411 427 436 443
PLATFORM HEIGHT (m)
TOWER Total Self-weight (kgs)
Quantity Schedule
1450 Width Towers
BoSS 1450 Ladderspan to EN 1004: Available in 2 lengths - 1.8m and 2.5m See pages 10 and 30 for stabiliser positions.
Internal UseInternal/External Use

BoSS Ladderspan User Guide
9
The MAXIMUM SAFE WORKING LOAD (the combined weight of
the users, tools and materials) that may be placed on the tower is the
total weight less than the self-weight of the tower. The total weight for
the towers shown in the schedule is 950kg.
Example 1:
A 1450 tower built using the 3T method with a 4.2m platform height
and a platform length of 1.8m has a self-weight of 175kg.
950kg
Total Weight -175kg Self-weight =775kg maximum safe working load (users, tools and materials)
Example 2:
A 1450 tower built using the 3T method with a 11.7m platform height
and a platform length of 2.5m has a self-weight of 436kg.
950kg
Total Weight -436kg Self-weight =514kg maximum safe working load (users, tools and materials)
For greater heights and loads, consult BoSS for guidance.
Quantity Schedule
NUMBER OF WORKING PLATFORMS ALLOWED
1450 Width Towers
PLATFORM LOADING
On a 1450 tower a platform may comprise of a single deck or two
decks placed side by side. The maximum safe working load
(the combined weight of the users, tools and materials) that may be
placed on a platform is 275kg. This must be evenly distributed over
either one deck, or two decks placed side by side.
The quantities on page 7 and 8, will enable BoSS towers to be built
safely and therefore comply with the requirements of the Work at
Height Regulations. They include double guardrails to all platforms,
and toeboards will need to be added if any levels are used as working
platforms and for storage of materials.
EN 1004 requires platforms at least every 4.2m, and these measures
will exceed that requirement.

bossaccesstowers.com 10
Quantity Schedule
1450 Width Towers
BALLAST: Internal/External Use
There is no requirement for ballast on 1450 towers if using stabilisers
as detailed in the table on page 8.
MOBILE OUTRIGGERS
MP16 outriggers can be used instead of SP15 stabilisers, as detailed
below. Mobile outrigger kits comprise:
MOBILE OUTRIGGER KIT
MP16 Mobile Outrigger 4
125/150/200mm Castor
(Use same diameter castors as
on tower)
4
250mm Adjustable leg 4
Plan Braces 4
The above components replace:
SP15 Stabiliser 4
STABILISERS
To improve rigidity, larger stabilisers can be used at a lower level than
shown in the table on page 8.
Angle of Stabiliser 1450 TOWER
X
X
90%
PLATFORM LENGTH 1.8M PLATFORM LENGTH 2.5M
SP7 X= 3351 X= 3629
SP10 X= 4789 X= 5100
SP15 X= 5520 X= 5838
Stabiliser feet should form a square as shown in the diagram and
table above.
Double width 1450 Towers Dimension X

BoSS Ladderspan User Guide11
3.2
1.2
3.7 1.7
4.2 2.2
4.7 2.7
5.2 3.2
5.7 3.7
6.2 4.2
6.7 4.7
7.2 5.2
7.7 5.7
8.2 6.2
8.7 6.7
9.2 7.2
9.7 7.7
10.2 8.2
10.7 8.7
11.2 9.2
11.7 9.7
12.2 10.2
12.7 10.7
13.2 11.2
13.7 11.7
14.2 12.2
4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4
4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4
1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1
1 1 1 2 1 2 2 3 2 3 3 4 3 4 4 5 4 5 5 6 5 6
1 1 1 2 1 2 2 3 2 3 3 4 3 4 4 5 4 5 5 6 5 6
1 1 1* 2 2 2 2 3 3 3 3 4 4 4 4 5 5 5 5 6 6 6 6
6 6 6 6 10 10 10 10 14 14 14 14 18 18 18 18 22 22 22 22 26 26 26
2 3 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
Adjustable leg assembly
125/150/200mm Castor
850 2 Rung Ladder Frame
850 2 Rung Span Frame 850 3 Rung Ladder Frame 850 3 Rung Span Frame 850 4 Rung Ladder Frame 850 4 Rung Span Frame
1.8m and 2.5m Trap Door Deck 1.8m and 2.5m Horizontal Brace (red) 2.1m and 2.7m Diagonal Brace (blue) 1.8m and 2.5m Side Toeboard
COMPONENT WORKING HEIGHT (m)
PLATFORM HEIGHT (m)
IMPORTANT: Please ensure you also read the Quantity Schedule on page 12. * If you are unable to position the working platform easily from the ground, you may require an additional fixed platform for this tower height. BoSS 850 Ladderspan to EN 1004: Available in 2 lengths - 1.8m and 2.5m
Quantity Schedule
850 Width Towers
Internal UseInternal/External Use - Towers under 2.5m are outside of the scope of EN1004

bossaccesstowers.com 12
Quantity Schedule
850 Width Towers
COMPONENT WORKING HEIGHT (m) PLATFORM HEIGHT (m)
3.2 1.2
3.7 1.7
4.2 2.2
4.7 2.7
5.2 3.2
5.7 3.7
6.2 4.2
6.7 4.7
7.2
5.2
7.7
5.7
8.2 6.2
8.7 6.7
9.2
7.2
9.7
7.7
10.2
8.2
10.7
8.7
11.2
9.2
11.7
9.7
12.2 10.2
12.7 10.7
13.2 11.2
13.7 11.7
14.2 12.2
0.6m End Toeboard 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 Toeboard Holder 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 SP7 Fixed Stabiliser 4 4 4 4 4 4 4 SP10 Telescopic Stabiliser 4 4 4 4 4 4 4 4 4 4 4 4 4 SP15 Telescopic Stabiliser 4 1.8m TOWER Total Self-weight (kgs) 72 79 106 126 139 146 151 172 186 204 210 230 243 250 270 276 289 296 301 321 335 341 347 2.5m TOWER Total Self-weight (kgs) 84 90 117 143 158 165 172 198 225 233 239 264 280 286 382 318 334 341 347 372 488 395 401
See page 14 and 30 for stabiliser positions. BoSS 850 Ladderspan to EN 1004: Available in 2 lengths - 1.8m and 2.5m
Internal UseInternal/External Use - Towers under 2.5m are outside of the scope of EN1004

BoSS Ladderspan User Guide
13
The MAXIMUM SAFE WORKING LOAD (the combined weight of the
users, tools and materials) that may be placed on the tower is the
total weight less the self-weight of the tower. The total weight for the
towers shown in the schedule is 950kg.
Example 1:
An 850 tower built using the 3T method with a 4.2m platform height
and a platform length of 1.8m has a self-weight of 151kg.
950kg
Total Weight -151kg Self-weight =799kg maximum safe working load (users, tools and materials)
Example 2:
An 850 tower built using the 3T method with a 11.7m platform height
and a platform length of 2.5m has a self-weight of 408kg.
950kg
Total Weight -408kg Self-weight =542kg maximum safe working load (users, tools and materials)
For greater heights and loads, consult BoSS for guidance.
Quantity Schedule
NUMBER OF WORKING PLATFORMS ALLOWED
850 Width Towers
PLATFORM LOADING
On an 850 tower a platform comprises of a single deck only. The
maximum safe working load (the combined weight of the users, tools
and materials) that may be placed on a platform is 275kg, evenly
distributed over the deck.
The quantities on pages 11 and 12, will enable BoSS towers to be
built safely and therefore comply with the requirements of the Work
at Height Regulations 2005. They include double guardrails to all
platforms, and toeboards will need to be added if any levels are used
as working platforms and for storage of materials.
EN 1004 requires platforms at least every 4.2m, and these measures
will exceed that requirement.

bossaccesstowers.com 14
Quantity Schedule
850 Width Towers
BALLAST: Internal/External Use
There is no requirement for ballast on 850 towers if using stabilisers
as detailed in the table on page 12.
MOBILE OUTRIGGERS
MP16 outriggers can be used instead of SP15 stabilisers, as detailed
below. Mobile outrigger kits comprise:
MOBILE OUTRIGGER KIT
MP16 Mobile Outrigger 4
125/150/200mm Castor
(Use same diameter castors as
on tower)
4
250mm Adjustable leg 4
Plan Braces 4
The above components replace:
SP15 Stabiliser 4
STABILISERS
To improve rigidity, larger stabilisers can be used at a lower level than
shown in the table on page 12.
X
X
90%
PLATFORM LENGTH 1.8M PLATFORM LENGTH 2.5M
SP7 X= 2994 X= 3201
SP10 X= 4458 X= 4734
SP15 X= 5195 X= 5485
Stabiliser feet should form a square as shown in the diagram and
table above.
Single Width 850 Towers Dimension X

BoSS Ladderspan User Guide
15
Assembly Procedure
Mobile Towers - 3T Method
ASSEMBLY AND DISMANTLING PROCEDURES
To comply with the Work at Height Regulations, we show
assembly procedures with platforms every 2 metres in height,
and, the locating of guardrails in advance of climbing onto a
platform to reduce the risk of a fall.
All platforms feature double guardrails on both faces of either
individual platforms or fully decked levels.
All guardrails should be 1 and 2 rungs (0.5m and 1.0m) above
platforms.
Never stand on an unguarded platform positioned above
the rst rung of a tower. If your risk assessment shows it
necessary, you may also need to guardrail platforms at this
level.
Always start building with the smallest height frames at the
base of the tower:
When building a BoSS Tower:
PLATFORM HEIGHT IN METRES FRAME AT BASE
1.7, 2.2, 3.7, 4.2, 5.7, 6.2, 7.7, 8.2, 9.7, 10.2, 11.7, 12.2 2 rung
2.7, 4.7, 6.7, 8.7, 10.7 3 rung
1.2, 3.2, 5.2, 7.2, 9.2, 11.2 4 rung
Where all 3 frame heights are used in a tower, start with 2 rung
frames at the base, with the 3 rung frames next and the 4 rung
frames on the top. Refer to the quantity schedules for detail.
TO DISMANTLE A BoSS LADDERSPAN TOWER
Remove toeboards, and pass down the tower.
Unclip farthest end of braces and immediately go to protected
trapdoor position on ladder to complete removal.
Remove upper platforms from protected platform levels below.
Pass removed components out of the tower to a colleague.

bossaccesstowers.com 16
Safety Checklist
Mobile Towers - 3T Method
CHECKLIST
Ensure all brace claws operate and lock correctly prior to erection
Inspect components prior to erection
Inspect tower prior to use
Tower upright and level
Castors locked and legs correctly adjusted
Diagonal braces tted
Stabilisers/outriggers tted as specied
Platforms located and windlocks on
Toeboards located
Check guardrails are tted correctly. See illustration below

BoSS Ladderspan User Guide
17
Assembly Procedure
Push castor into adjustable leg. Push Castor /adjustable leg
assemblies into 2 rung span frame. Lock castors. Repeat
procedure with 2 rung ladder frame.
It is recommended that for ease of levelling a gap of 50mm is left
between the bottom of the leg and the adjustable nut. Adjustable
Legs are for levelling only. You must not adjust all four to gain extra
height.
NB: Base plates can be tted to adjustable legs in lieu of castors
if it is not necessary to move the tower.
Mobile Towers - 1450 3T Method
Always start building with the smallest height
frames at the base of the tower:
PLATFORM HEIGHT IN METRES FRAME AT BASE
1.7, 2.2, 3.7, 4.2, 5.7, 6.2, 7.7, 8.2, 9.7, 10.2, 11.7, 12.2 2 rung
2.7, 4.7, 6.7, 8.7, 10.7 3 rung
1.2, 3.2, 5.2, 7.2, 9.2, 11.2 4 rung
ASSEMBLY FOR 1450 TOWERS
Where all 3 frame heights are used in a tower, start with 2 rung
frames at the base, with the 3 rung frames next and the 4 rung frames
on the top. Refer to the Quantity Schedules for detail.
The procedure illustrated shows 4.2m platform height tower starting
with a 2 rung frame.
BoSS recommend two persons are used to build BoSS Towers.
Above 4m height, it is essential that at least two persons are
used. Only climb the tower from the inside.
1

bossaccesstowers.com 18
Fit one horizontal brace (red) onto the vertical of a span
frame, just above the bottom rung, with the claw facing
outwards. The frame will now be self supporting.
Note: All locking claws must be opening before tting.
2
Assembly Procedure
Locked
Position the ladder frame as shown and t the other end of
the horizontal brace on to the vertical (just above the bottom
rung). Fit a second horizontal brace between the bottom rungs on the
other side of the frames to square the tower.
3

BoSS Ladderspan User Guide
19
4
Assembly Procedure
Fit 2 additional end frames, ensuring the frame interlock
clips are engaged. Fit 2 diagonal braces (blue) in opposing
directions, between the 1st and the 3rd rungs. Ensure the frames
are vertical and level by checking with a spirit level and setting the
adjustable legs as required.
IMPORTANT - Only use the adjustable legs to level the tower and
not to gain extra height.