Instruction number 1- Stability inland waterway vessels

a. This ItoRO replaces ItoRO no.1 version 2013.
b. Unless expressly provided otherwise, this ItoRO is applicable for stability calculations made for ships certified after 01 January 2020 and for stability calculations after conversions or alterations of the ship submitted for approval after 01 January 2020.
c. Where in this instruction ‘ADN’ is mentioned, it refers to The European Agreement concerning the International Carriage of Dangerous Goods by Inland Waterways.
The ADN Administrative Committee agreed upon a number of interpretations of the ADN. These interpretations are quoted as ADN interpretations and are available at the UNECE website.
d. In those cases the Netherlands inland waterway regulations, the ES-TRIN and/or the ADN have different intact or damage stability requirements, both criteria shall be met. For instance: a containership of more than 110 meter in length, shall meet both the requirements of containerships and the requirements for ships of more than 110 meter in length.

a. Tankers with a length shorter than 110m and without ADN certification. In order to comply with the third paragraph of Article 3.03 of ES-TRIN, the stability of tankers, whose cargo tanks have a width greater than 70% of the width on the waterline, must be demonstrated by of a calculation that is submitted to the Inspection Body / Classification society for approval. In this calculation, the ship is loaded to the maximum draft and all tanks have a free fluid moment.
The intact stability criteria according to the ADN type N tanker are used as a guideline for the stability requirements. The ADN interpretations are used where relevant
b. For tankers of less than 110 meters in length for the transport of liquids that are not subject to ADN, no special stability requirements are adopted. However, the cargo tanks have a large ‘free surface moment’ which may have a big impact at the ship’s stability. Following the general obligation that the vessels stability corresponds to their intended use, in those cases the tanks have a breadth greater than 0.7xB (breadth of the ship as defined in ES-TRIN article 1.01.4.21) an approved stability calculation is mandatory.
For this calculation the ship is loaded to the maximum draft and all tanks for cargo and consumables have a ‘maximum free surface effect’ The intact stability criteria should be used according to ADN type N tankers (see ADN article 9.3.3.14 tankers type N).
(ES-TRIN Article 3.02 paragraph 3: Stability in line with intended use)

a. If the heeling test cannot achieve a sufficient inclination angle, or if the execution of the heeling test entails insurmountable technical problems, a calculation of the weight and center of gravity can be made instead. The result of the weight calculation must be checked by means of measurements of the draft, the difference must not exceed more than ± 5%.
(ES-TRIN article 19.01 third paragraph: Heeling test)
b. Superstructures can be considered buoyant in the (damage) stability calculations. It may be assumed that decks and attachments of superstructures to the hull are of sufficient strength to withstand the water pressure. In case of doubt, the strength shall be proven by calculation and improved where necessary.
(ES-TRIN article 19.03 paragraph 8: Buoyancy of the vessel in the event of flooding shall be proven)
c. The accommodation access door shall be considered as weather tight. If the access is fitted with an approved watertight door, it can be considered as watertight. In addition the accommodation have to be fitted with an emergency exit and this exit should be considered as an weather tight opening. If a window is used as an emergency exit, it should meet all the requirements for emergency exits.
(ES-TRIN article 1.01.6.1 en article 1.01.6.2: definitions watertight and weather tight)
d. In case of bottom damage, the penetration depth is measured from base line.
(ES-TRIN article 19.03 paragraph 9: requirements for damage stability)
e. The extent of damage is determined at the maximum draught as indicated on the declaration of maximum draught, by the measuring of the length and height of the penetration depth, right-angle to the plane of keel and stems.
(ES-TRIN article 19.03 paragraph 9; requirements for damage stability)
f. Ventilation and other ducts penetrating watertight bulkheads as specified in article 19.02.13(a), shall be led above the waterline corresponding to the worst possible flooding. Such a penetration need not be considered as an opening according 19.03.9(c), and consequently the height of the opening above the damaged waterline may be 0 mm above the damaged waterline.
(ES-TRIN article 19.02.13(a): penetration of watertight bulkheads by piping or ducts)

g. Where watertight bulkheads on passenger ships are not installed up to the bulkhead deck, the point of flooding is to be at least 20 cm above the worst damaged waterline. However, this interpretation shall only apply to passenger ships who receive their first Community Certificate on or after 01 January 2020.
(ES-TRIN article 19.02.5: where there is no bulkhead deck, bulkheads shall extend to a height at least 20 cm above the margin line.)
h. Windows which can be opened, are to be considered as a weather tight opening.
(ES-TRIN article 19.02 paragraph 16: Windows may be below the margin line)
i. the interpretation related to air pipe openings (including goosenecks) shall only apply to passenger ships who receive their first Community Certificate on or after 01 January 2020. On passenger ships who receive their first Community Certificate before that date, air pipes fitted with automatic closing devices may be considered as watertight.
(ES-TRIN article 1.01.6.1 en article 1.01.6.2: definitions watertight and weather tight)
j. The openings and flow times of cross flooding devices may also be determined with IMO Resolution MSC.362(92) (as may be amended) .
(ES-TRIN article 19.03 paragraph 13)
k. Undecked passenger ships certified for inland water ways zone 3 should have sufficient reserve buoyancy after flooding. This buoyancy is considered sufficient if the ship in undamaged flooded condition has a freeboard of at least 0.05m. Compliance with this requirement can be proven by a calculation or a practical test.
(Binnenvaartregeling, Appendix 3.4, article 3, paragraph 1)

4. Containerships

a. The stability calculations are made for a ship on even keel.
(ES-TRIN article 27.02 and article 27.03, method for stability calculation)
The stability book contains a calculation scheme for the boat master. An example of a calculation scheme can be found in Annex A of this Instruction.
(ES-TRIN article 27.01, paragraph 2d: Instruction for use or example of calculation for the boat master)
b. If the calculation of the KG’zul is based on the ships’ hull, the light ship weight should be determined by the unloaded weight of the tonnage certificate. If no hull form is used and the displacement is derived from the tonnage certificate, the light ship weight is determined by the following formula:
Light ship weight = L x B x T x 0.8. Where, ‘T’ is the unloaded draft according to the tonnage certificate. The vertical center of gravity is in both cases 60% of the depth.
(ES-TRIN article 27.02, paragraph 3: Approach of KM)
c. When KG’zul is calculated by the formula stated in article 27.02 paragraph 2; the freeboard F is taken as the smallest freeboard of the vessel, not the effective freeboard at ½ L.
(ES-TRIN article 27.02, paragraph 2)

a. Superstructures can be considered buoyant in the (damage) stability calculations. It may be assumed that decks and attachments of superstructures to the hull are of sufficient strength to withstand the water pressure. In case of doubt, the strength shall be proven by calculation and improved where necessary.
(ES-TRIN article 27.03 paragraph 3:The applicant shall prove, by means of a calculation based on the method of lost buoyancy, that the buoyancy and stability of the vessel are appropriate in the event of flooding.
b. The entrance doors shall be considered as weather tight opening. In case an approved watertight door is fitted, the entrance may be considered as watertight. However, in that case the space shall be fitted with an escape which is considered in the stability calculation as weather tight opening. In case a window is considered as escape, the window shall comply with all requirements for escapes (ES-TRIN article 1.01.6.1 en article 1.01.6.2: definitions watertight and weather tight)
c. In case of bottom damage, the penetration depth is determined from the baseline (top of the bottom plates/ underside floors).
(ES-TRIN article 27.03 paragraph 4b: Extent of bottom damage)
d. The extent of damage is determined by the measuring of the length and height of the penetration depth, right-angle to the plane of keel and stems.
(ES-TRIN article 27.03, paragraph 4a: Extent of side damage)
e. When the engine room consists of more than one compartment, only transverse bulkheads of the compartment containing the main engine shall be considered as undamaged.
(ES-TRIN article 27.03 paragraph 4- c: Bulkheads in damaged zone)
f. Non-fixed windows shall be considered as weather tight opening.
(ES-TRIN article 27.03 paragraph 5-c: non watertight openings above the damaged waterline)
g. Where applicable, the ADN interpretations as referred to under 1f equally apply to these ships.
(ES-TRIN article 1.01.6.1 en article 1.01.6.2: definitions watertight and weather tight)

a. For all ships with hoisting or lifting equipment, an on board load test in required. Apart from this on board test, on ships with lifting gear or a crane on board capable of hoisting 2000 kg or more a stability calculation shall be made.
Limiting criteria for the mandatory on board load test are:
- No deck immersion;
- Maximum heeling angle below 10 degrees; and
- Openings at least 10 cm above heeled waterline.
For ships with a crane with a working load of more than 2000 kg the allowable heeling moment Ml can be calculated with the following formula:

With:
B= beam as defined in article 1.01.4.19 van de ES-TRIN;
T= draught as defined in article 1.01.4.23 van de ES-TRIN;
H= depth as defined in article 1.01.4.22 van de ES-TRIN;
GM if known or else:

When the maximum (combined) moment induced by the lifting gear does not exceed the allowable heeling moment Ml, sufficient stability is proven by the calculated moment Ml.
When the maximum (combined) moment induced by the lifting gear exceeds the allowable heeling moment Ml, a stability calculation in accordance with the requirements of the Directive and ROSR chapter 22 shall be made.
(ES-TRIN article 14.12, paragraph 6: lifting gear)
b. For the purpose of stability calculations, the vertical center of gravity of spud poles shall be located at the vessels vertical center of gravity. For the calculation of the windage area, the spud poles shall be considered at the highest position.
(ES-TRIN article 22.07 paragraph 1: proof of sufficient stability)
c. When calculating the stability range for compliance with article 22.08(b), the righting lever curve may be taken into account upto 30 degrades. Within this range deck edge immersion is acceptable provided that the other requirements relating to freeboard and safety distance of article 22.08 are also met.
d. The moment induced by ‘other mechanical devices’ shall be taken into account when making the stability calculations. For cranes and lifting gear, this moment is the maximum moment the crane is capable of. The centre of gravity of the loaded mass shall be determined according normal naval architectural practice. The stability calculation shall be made for the maximum permissible draft of the ship. In this respect reference is also made to article 6f of this ItoRO.
(ES-TRIN article 22.07, paragraph 4: Heeling moment mechanical devices)
e. The freeboard shall be determined according the definition in article 1.01.4.5 This results in the lowest deck in the side being the deck where the freeboard is measured.
(ES-TRIN article 22.05: Reserve freeboard)
f. When the approved stability calculation results in operational limitations, these limitations and the following note shall be included on the vessels certificate under item 52: ‘An approved stability document with doc.no. xxxx must be present on board showing the stability boundary conditions.’

For tankers

The vertical center of gravity is: S2 / S1 = ………………..m.
Free surface effect correction: S3 / S1 = .……………….m.
(waterballast, cargo and consumables)

Add this up together.

Vertical center of gravity (KG’) is: ………………..m
Maximum allowable KG’zul is: ………………..m
The vertical center of gravity (KG’) shall be smaller than KG’zul.

For container ships

H1 = height of upper side of tanktop + 0,5 x height of first tier
H2 = height of upper side of tanktop + height of 1st tier + 0,5 x height of 2nd tier etcetera
The vertical centre of gravity is: S2 / S1 = ………………..m.
Correction for free surface effects is: S3 / S1 = ………………..m.
(waterballast and consumables)

Add these 2 up together.

Vertical centre of gravity (KG’) is: ………………..m
Maximum alowable KG’zul is: ………………..m
The vertical centre of gravity (KG’) shall be smaller than KG’zul.