An international shore connection (ISC) is a standardized coupling that lets shore-based or another ship’s fire pumps supply water to a vessel’s fire main. It matters most in a foreign or remote port, where a ship’s own pumps may not be enough to fight a fire alone.
What Is an International Shore Connection?
The international shore connection is a standardized flange coupling carried aboard ships that lets external firefighting water be supplied to the ship’s fire main. It connects a shore hydrant or another vessel’s hydrant to the ship’s own fire system.
Every SOLAS-class ship carries the same flange dimensions. Any port or vessel’s fire hose can couple to it, regardless of flag state or hose thread standard. That universality is the entire point of the design.
The ISC is easy to overlook — it sits in its box for years without use. That’s exactly why fire drills should include physically attaching the coupling to a hydrant, not just a visual check.
What Does SOLAS Require for the International Shore Connection?
SOLAS Chapter II-2, Regulation 10, paragraph 2.1.7 sets the requirement. Every ship of 500 gross tonnage and upwards must carry at least one international shore connection complying with the Fire Safety Systems (FSS) Code.
SOLAS Regulation II-2/10, Paragraph 2.1.7
2.1.7.1 — Ships of 500 gross tonnage and upwards shall be provided with at least one international shore connection complying with the Fire Safety Systems Code.
2.1.7.2 — Facilities shall be available enabling such a connection to be used on either side of the ship.
The FSS Code, Chapter 2, sets the exact flange dimensions covered in the next section. The ship’s fire hose and fire main arrangement must be compatible with this same standard connection.
What Are the Dimensions of the International Shore Connection?
The FSS Code fixes one set of dimensions for every ISC flange worldwide. Outside diameter is 178 mm, inside diameter is 64 mm, and the bolt circle is 132 mm. Four bolt holes, four bolts, four nuts, and eight washers complete the unit.
| Description | Dimension |
|---|---|
| Outside diameter | 178 mm |
| Inside diameter | 64 mm |
| Bolt circle diameter | 132 mm |
| Flange slots | 4 holes, 19 mm diameter, spaced equidistantly on the bolt circle |
| Flange thickness | 14.5 mm minimum |
| Bolts and nuts | 4, each 16 mm diameter, 50 mm length |
| Washers | At least 8 |
The flange must be made of steel or another suitable material, and the coupling itself must be gasketed for a watertight seal under pump pressure. A wire rope or chain often secures the blank cap when the coupling isn’t in use.
What Is Inside the International Shore Connection Box?
The ISC box holds the coupling flange itself, four bolts, four nuts, at least eight washers, and a spanner sized to fit those bolts. A gasket for the mating face is usually stored alongside it.
- 1 flange coupling (178 mm OD, 64 mm ID, 132 mm bolt circle)
- 4 bolts, 16 mm diameter, 50 mm length
- 4 nuts, matched to the bolts
- 8 washers minimum
- 1 spanner sized to the bolt/nut fitting
- 1 gasket for the mating flange face
The box itself is stencilled “International Shore Connection” or “ISC” in a contrasting colour. That marking makes it identifiable at a glance during a port state control inspection or an emergency.
Where Is the International Shore Connection Located on a Ship?
The ISC box is normally fitted on both sides of the accommodation block, close to the gangway. That placement lets shore firefighters or another vessel’s crew reach and connect it quickly, without searching the deck during an emergency.
The fire control plan shows the exact number and location of every ISC unit carried on board. Officers should confirm the plan matches the physical installation during each fire drill, not just read it once at handover.
How Do You Operate the International Shore Connection?
The ISC connects in one of two ways: bolted directly to a fire hydrant, or fitted between a fire hose and an external hydrant. Both methods feed outside water into the ship’s own fire main.
- Bolt the ISC flange directly onto the ship’s own fire hydrant outlet.
- Connect the ISC to a fire hose, then couple that hose to a shore hydrant or another vessel’s hydrant if the ship is at anchor or adrift and needs outside assistance.
Before connecting, crew should confirm the shore or receiving vessel’s pump pressure won’t exceed the ship’s fire main rating. An isolation valve upstream of the coupling lets the connection be shut off without draining the whole fire main.
How Does the ISC Differ from a Shore Connection Isolation Valve?
The ISC is the coupling itself — the standardized flange that physically joins an external hose to the ship. The isolation valve is a separate fitting on the ship’s side of that coupling.
The valve lets the crew shut off flow to the ISC branch without depressurizing the rest of the fire main. Not every ISC installation has one, but where fitted, it sits between the fire main and the ISC flange itself.
How Is the International Shore Connection Maintained?
Maintaining the ISC is a routine duty, usually assigned to the third officer, and it matters because the coupling sees almost no use between emergencies. Regular greasing and painting keep the flange from seizing or corroding.
The coupling should be bolted to a fire hydrant during scheduled fire drills to confirm it still fits and seals properly. This is the only way to catch a warped flange or damaged gasket before an actual emergency.
Inspection covers the flange face for brittleness, tears, or corrosion, plus the bolts, nuts, and washers for rust. Any washer, bolt, or nut showing rust should be replaced immediately, since a failed fastener under pump pressure is a real hazard.
What Do Surveyors Check on the International Shore Connection?
A surveyor checks that the ISC’s dimensions match the FSS Code and its flange face is undamaged. The box must be marked, accessible, and complete with its bolts, nuts, washers, spanner, and gasket. That standard applies whether the review is a SOLAS, FSS, or port state control inspection.
Common deficiencies include missing bolts or washers, a corroded or pitted flange face, and a box that’s been painted shut or buried behind stowed gear. On older or converted tonnage, a non-standard flange fitted years ago sometimes turns up too.
A surveyor will also cross-check the physical installation against the fire control plan’s stated ISC locations and count. A missing, damaged, or inaccessible ISC is a routine fire-safety deficiency category in PSC detentions, not a rare finding.
Frequently Asked Questions
What does ISC stand for in shipping?
ISC stands for international shore connection. It is the standardized flange coupling that lets a ship’s fire main receive water from a shore hydrant or another vessel’s fire pump.
How many international shore connections must a ship carry?
SOLAS Chapter II-2, Regulation 10, paragraph 2.1.7.1 requires at least one ISC on every ship of 500 gross tonnage and upwards. Regulation 2.1.7.2 requires it to be usable from either side of the ship.
What is inside the international shore connection box?
The box holds the flange coupling, four bolts (16 mm diameter, 50 mm length), and four matching nuts. It also carries at least eight washers, a spanner, and a gasket for the mating face.
What size are the bolts on the international shore connection?
The FSS Code specifies four bolts, each 16 mm in diameter and 50 mm long. They fit through four 19 mm holes spaced on a 132 mm bolt circle.
How is the international shore connection marked?
The ISC box is stencilled “International Shore Connection” or “ISC” in a contrasting colour. That marking lets it be identified quickly during an inspection or an emergency.
Is the international shore connection used for sewage or garbage discharge?
No. The ISC is a firefighting fitting only, coupling the ship’s fire main to an external water supply. Sewage and garbage discharge use separate, unrelated shipboard systems.
What is the spanner in the ISC box used for?
The spanner is sized to fit the four bolts and nuts on the ISC flange. It lets crew bolt or unbolt the coupling quickly without hunting for a matching tool.
How often should the international shore connection be inspected?
Inspect it at every scheduled fire drill by attaching it to a hydrant. Check the flange, bolts, nuts, and washers for corrosion as part of routine fire equipment maintenance rounds.
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