Tie-down lashing.

In the force-locking tie-down lashing method, the load to be secured is spanned with lashing equipment, pressed onto the loading surface and thus secured on all sides.

To prevent the load from slipping, the contact pressure between the load and the loading surface and thus the frictional force is increased by pre-tensioning forces. The pre-tensioning force (S_TF) should be the same on all spans.

Calculation formula for a free-standing, stable load unit:

Massenkräfte beim Niederzurren Darstellung

Abbreviation	Definition	Explanation according to VDI 2700
a	Acceleration of the load	Maximum acceleration of the load for the type of transport in question
f	Acceleration coefficient	Coefficient for determining the amount and direction of the mass force of the load
f_lv	Forward longitudinal acceleration coefficient	= 0,8 during braking*
f_lh	Longitudinal acceleration coefficient to the rear	= 0,5 during start-up*
f_q	Lateral acceleration coefficient to the side	= 0,5 when cornering*
f_V	Vertical acceleration coefficient downwards	= 1,0*
F_G	Weight force	Force which with the load acts on a horizontal loading surface
F_iS	Pre-tensioning force as lashing equipment	Resistance force that mus be applied in addition to the dynamic frictional force, e.g. by lashing equipment, to secure a load against inertial forces
g	Acceleration due to gravity	g = 9,81 m/s²
k	Coefficient	Resistance force that must be applied in addition to to the dynamic frictional force, e.g. by lashing equipment, to secure a load against inertial forces
n	Number of lashing equipment / overtensions
m	Mass of the load	Mass to be secured
α	Vertical angle	angle between lashing equipment and loading area of a means of transport
μ	Coefficient of friction	Coefficient for determining the friction between the load and the resepective base during the movement of the load relative to the loading surface

*The acceleration values in the table refer to a vehicle with a gross vehicle weight rating of more than 3.5 t.

For safety reasons, lashing equipment must not be pre-tensioned with more than 50% of the maximum lashing capacity (LC) in accordance with VDI 2700 Sheet 2 (July 2014). Dynamic forces occurring during the journey can otherwise overload the belts.
The pre-tensioning force should be checked regularly during the journey (especially shortly after starting the journey).
To ensure pre-tensioning on both sides of the load when lashing down, we recommend edge protectors, which ensure a more even distribution of force in the lashing equipment and also offer better protection against sharp edges.

Aids

Dolezych Simple Method^©
Trucker's Disc
iDolores (app for smartphones)

The calculation for tie-down lashing.

When calculating the tie-down lashing, the result must always be rounded up so that sufficient lashing straps are always used.
The units must always be adjusted to the so-called SI units. For example, the weight of the load must always be given in kg and the tension in the belt in N.
A lower transmission coefficient than k 0 1.8 can occur if the lashing straps are passed over particularly rough surfaces, for example. In this case, please take suitable measures to ensure force distribution in the lashing system (e.g. using edge sliders).

If you want to make things even easier, use our Dolezych Simple Method^©for lashing down

In the table below, the number of lashing straps required is calculated using the following criteria:

Pre-tensioning force (S_TF) of our product portfolio
Coefficient of friction (0.1-0.6)
Lashing angle α (35°, 60° or 90°)
Load weight / payload (up to 16 t )

For lashing angles between 35°, 60° and 90°, always use the next lower lashing angle from the table. Vertical angles below 35° are uneconomical and are therefore not taken into account.

Calculation example according to VDI 2700 Sheet 2 (July 2014)

The following is specified for the calculation example:

Weight of the load: m = 6,000 kg

Coefficient of friction: μ = 0.3

Lashing angle: α = 60°

Transfer coefficient: k = 1.8

Acceleration due to gravity: g = 9.81 m/s2

Acceleration coefficient: f = 0.8

Pretensioning force value: FiS (see below)

The pre-tensioning force S^TF on the side opposite the tensioning device corresponds to at least 50 % (k = 1.8)
Free-standing, homogeneous, stable load
At least two overstresses
All non-integer table values are rounded up
For our 50 mm lashing straps

Vorspannkraft STF	μ	Anzahl der erforderlichen Zurrgurte
Vorspannkraft STF	μ	1 t 35° / 60° / 90°			2 t 35° / 60° / 90°			3 t 35° / 60° / 90°			4 t 35° / 60° / 90°
DoZurr5000 & DoRapid5000 & DoPremium5000 – 300 daN
300 daN	0,1	15	13	11	30	26	22	44	30	24	66	44	33
	0,3	6	5	4	12	11	9	17	13	11	25	18	14
	0,6	4	3	2	7	6	5	11	8	6	16	11	8
DoZurr4000 – 320 daN
320 daN	0,1	14	12	10	28	24	20	42	28	22	62	42	32
	0,3	6	5	4	11	10	8	16	12	10	23	16	13
	0,6	3	2	2	5	4	3	8	6	4	11	8	6
DoTension420 – 420 daN
420 daN	0,1	11	10	8	21	18	15	31	21	18	47	31	24
	0,3	5	4	3	8	7	6	13	9	7	18	13	10
	0,6	2	2	2	4	3	2	6	4	3	8	6	4
DoZurr5000 mit DoMulti500 oder Do2Step – 500 daN
500 daN	0,1	14	9	8	27	16	16	40	27	23	60	40	30
	0,3	5	4	3	10	7	6	13	9	8	20	13	9
	0,6	2	2	2	2	2	2	3	2	2	4	3	2
DoZurr5000 oder DoPremium5000 jeweils mit DoMulti500 – 600 daN
600 daN	0,1	12	8	7	23	15	13	35	23	20	52	30	26
	0,3	5	4	3	9	6	5	12	8	7	18	11	9
	0,6	2	2	2	2	2	2	2	2	2	3	2	2
DoZurr4000 mit DoMulti – 680 daN
680 daN	0,1	10	7	6	20	15	12	30	20	17	45	26	23
	0,3	4	3	2	7	5	4	11	7	6	16	10	6
	0,6	2	2	2	2	2	2	2	2	2	2	2	2
DoTension720 mit DoMulti600 – 720 daN
720 daN	0,1	10	7	6	19	13	11	28	19	16	36	25	20
	0,3	4	3	2	7	6	5	11	8	6	16	11	8
	0,6	2	2	2	2	2	2	2	2	2	2	2	2