Equipment for Rational Securing of Cargo on Railway ... - Vinnova

MariTerm AB 2004-01-30 jvgRASLA
12.5 Allowable significant wave height <strong>for</strong> train ferries
For operations in a restricted area, reduction <strong>of</strong> the accelerations calculated in the previous
section may be considered. The RINA report Safety <strong>of</strong> passenger Ro-Ro vessels gives this
correction factor as:
f =
R
3
H
S
19.6
where H S is the actual significant wave height in the specific sea area and 19.6 is the greatest
probabilistic significant wave height in meters during a twenty year period <strong>for</strong> the North
Atlantic.
Wagons with towing hooks
The lowest allowable acceleration was obtained <strong>for</strong> the Rs 691 wagon. The acceleration is
2.83 m/s 2 when the lashings are fastened as in Case 1 and lashings are applied to each <strong>of</strong> the
two hooks. Comparing this acceleration by the transverse accelerations <strong>of</strong> the different ships
and utilizing the <strong>for</strong>mula above, a maximum significant wave height that each ship may
operate in can be calculated, as seen in the table below.
Ship a T, corr f R H S
Ship 1 6,0 0,47 2,1
Ship 2 5,1 0,56 3,4
Ship 3 6,1 0,46 2,0
Ship 4 5,9 0,48 2,1
Ship 5 7,0 0,41 1,3
Ship 6 6,0 0,47 2,1
Ship 7 6,5 0,44 1,6
14 kN
The acceleration is 2.98 m/s 2 when the lashing equipment is applied as in Case 2. The
maximum significant wave height that each ship may operate in with this configuration is
presented in the table below.
Ship a T, corr f R H S
Ship 1 6,0 0,50 2,4
Ship 2 5,1 0,58 3,9
Ship 3 6,1 0,49 2,3
Ship 4 5,9 0,50 2,5
Ship 5 7,0 0,43 1,5
Ship 6 6,0 0,50 2,5
Ship 7 6,5 0,46 1,9
26 kN
224