Ship Construction & Naval Architecture
International Shore, Bilge & Sewage Coupling Dimensions
The standard flange dimensions for the international shore connection, bilge coupling and sewage coupling every surveyor expects you to know.
Key Principles at a Glance 6 points
- Ships of 500 GT and above must have at least one International Shore Connection so that shore fire-fighting water can be supplied to the ship's fire main.
- The International Shore Coupling has an O.D of 178 mm, I.D of 64 mm, bolt circle diameter of 132 mm and flange thickness of 14.5 mm.
- The International Shore Coupling has 4 slots of 19 mm, 4 bolts and nuts of 16 mm diameter, 50 mm long.
- The Bilge Coupling has an O.D of 215 mm, bolt circle diameter of 183 mm, flange thickness of 20 mm, 6 slots of 22 mm, and 6 bolts and nuts of 20 mm diameter (I.D according to the pipe O.D).
- The Sewage Coupling has an O.D of 210 mm, bolt circle diameter of 170 mm, flange thickness of 16 mm, 4 slots of 18 mm, 4 bolts and nuts of 16 mm diameter, and a pipe inner diameter of 100 mm.
- Knowing these dimensions allows a ship to connect to shore facilities and to other ships, which is essential for fire-fighting assistance and for discharging sewage to a shore reception facility.
1. The International Shore Connection: Purpose & Requirement
The International Shore Connection is a standard flanged coupling carried on board so that a ship can be supplied with water from shore fire-fighting equipment, or from another ship, if her own fire pumps are unavailable.
Requirement:
- Ships of 500 GT and above must have at least one International Shore Connection.
- It is a universal standard, so the same flange will mate with shore hydrants and with other vessels worldwide.
How It Is Used:
- A suitable length of hose is connected to the shore hydrant (or another ship's pump).
- The International Shore Connection joins that hose to the ship's fire main.
- It is supplied complete with a gasket, four bolts and nuts, and a washer, kept ready for immediate use.
Interactive 3D: Shore, Bilge & Sewage Couplings
Orbit the three standard flanges, select any part to isolate it, then switch modes to compare the 178 mm shore (4-slot), 215 mm bilge (6-bolt) and 210 mm sewage (100 mm bore) couplings.
Loading interactive 3D couplings model…
2. International Shore Coupling Dimensions
The International Shore Coupling is a flat flange of standard dimensions so that it is interchangeable worldwide.
Standard Dimensions:
| Dimension | International Shore Coupling |
|---|---|
| Outside diameter (O.D) | 178 mm |
| Inside diameter (I.D) | 64 mm |
| Bolt circle diameter | 132 mm |
| Flange thickness | 14.5 mm |
| Slots in flange | 4 |
| Diameter of slot | 19 mm |
| Bolts & nuts | 4 / 4 |
| Diameter of bolt | 16 mm |
| Length of bolt | 50 mm |
| Pipe inner diameter | — |
3. Bilge & Sewage Coupling Dimensions
Bilge Coupling:
| Dimension | Bilge Coupling |
|---|---|
| Outside diameter (O.D) | 215 mm |
| Inside diameter (I.D) | According to O.D of pipe |
| Bolt circle diameter | 183 mm |
| Flange thickness | 20 mm |
| Slots in flange | 6 |
| Diameter of slot | 22 mm |
| Bolts & nuts | 6 / 6 |
| Diameter of bolt | 20 mm |
| Length of bolt | Suitable length |
| Pipe inner diameter | — |
Sewage Coupling:
| Dimension | Sewage Coupling |
|---|---|
| Outside diameter (O.D) | 210 mm |
| Inside diameter (I.D) | According to O.D of pipe |
| Bolt circle diameter | 170 mm |
| Flange thickness | 16 mm |
| Slots in flange | 4 |
| Diameter of slot | 18 mm |
| Bolts & nuts | 4 / 4 |
| Diameter of bolt | 16 mm |
| Length of bolt | Suitable length |
| Pipe inner diameter | 100 mm |
4. Comparison Table & Exam Notes
The three couplings compared side by side:
| Dimension | International Shore | Bilge | Sewage |
|---|---|---|---|
| O.D | 178 mm | 215 mm | 210 mm |
| I.D | 64 mm | According to pipe O.D | According to pipe O.D |
| Bolt circle dia | 132 mm | 183 mm | 170 mm |
| Flange thick | 14.5 mm | 20 mm | 16 mm |
| Slot in flange | 4 | 6 | 4 |
| Dia of slot | 19 mm | 22 mm | 18 mm |
| Bolt & nuts | 4 / 4 | 6 / 6 | 4 / 4 |
| Dia of bolt | 16 mm | 20 mm | 16 mm |
| Length of bolt | 50 mm | Suitable length | Suitable length |
| Pipe inner dia | — | — | 100 mm |
Why These Couplings Matter:
- International Shore Connection: Emergency fire-fighting assistance from shore or another ship — a lifesaving item during a major fire.
- Bilge Coupling: Allows the ship's bilge/fire line to be connected to shore pumps for pumping out or firefighting support.
- Sewage Coupling: Standard connection to discharge sewage to a shore reception facility, which is essential in ports and special areas.
Surveyor Asks
Memorise the key anchors — one coupling at a time:
- ISC = 178 mm O.D / 64 mm I.D / 132 mm bolt circle.
- Bilge = 215 mm O.D / 183 mm bolt circle / 6 bolts.
- Sewage = 210 mm O.D / 170 mm bolt circle / 100 mm bore.
Also state that ships of 500 GT and above must carry at least one International Shore Connection.