Statute Details
- Title: Merchant Shipping (Tonnage) Regulations
- Act Code: MSA1995-RG12
- Type: Subsidiary legislation (SL)
- Authorising Act: Merchant Shipping Act (Cap. 179), s 392
- Convention Basis: International Convention on Tonnage Measurement of Ships, 1969
- Current Version (as provided): Current version as at 27 Mar 2026
- Revised Edition: 1990 RevEd (25 Mar 1992)
- Key Parts: Part I (General Provisions); Part II (Determining Gross and Net Tonnages)
- Key Provisions (from extract): s 2 (definitions); s 3 (application); s 4 (interim scheme); s 5 (notification of alterations); s 6 (application for determination); s 7 (issue of certificate); s 8 (certificates by other Contracting States); s 9 (cancellation); s 10 (inspection); Part II ss 11–18 (measurement rules)
- Schedules: First Schedule; Second Schedule (Excluded spaces); Third Schedule
What Is This Legislation About?
The Merchant Shipping (Tonnage) Regulations set out the legal framework for determining the gross tonnage and net tonnage of Singapore ships. In practical terms, “tonnage” is a standardized measurement of a vessel’s size and useful capacity. These figures are used across maritime regulation—such as safety, manning, and operational rules—because many regulatory thresholds are expressed in tonnage.
The Regulations implement Singapore’s obligations under the International Convention on Tonnage Measurement of Ships, 1969. That Convention was designed to ensure that tonnage measurements are calculated using consistent methods worldwide, reducing disputes and improving regulatory uniformity. The Regulations therefore prescribe definitions, measurement methods, and certification processes that align with the Convention.
For practitioners, the Regulations are not merely technical. They create a compliance regime: ships within scope must have tonnages determined under the Regulations, certificates must be issued and maintained, and owners must notify the Director of Marine of alterations that may change tonnage. The Regulations also address transitional arrangements for certain ships and provide for recognition of certificates issued by other Contracting States.
What Are the Key Provisions?
1) Definitions and interpretive framework (s 2)
Section 2 provides the core terminology used throughout the Regulations. This includes definitions of “Certifying Authority” (the Director of Marine and other authorised organisations), “Contracting State,” “Convention,” “Director,” “existing ship” and “new ship,” and the central concepts of gross tonnage and net tonnage. It also defines “length” in a specific technical way (96% of the total length on a waterline at 85% of the least moulded depth, or an alternative length if greater), and “amidships” as the midpoint of the length.
Why this matters: tonnage calculations depend heavily on these defined measurements. A practitioner advising on a measurement dispute, a vessel modification, or a certification application will need to anchor the analysis in the statutory definitions rather than in commercial or class society descriptions.
2) Scope and when the Regulations apply (s 3)
Section 3 is the gateway provision. It specifies which ships are subject to tonnage determination under the Regulations, based on factors such as length, whether the ship is new or existing, the date of registration, and whether the ship undergoes substantial variations in existing gross tonnage.
Key features from the extract include:
- New ships of 24 metres and above are within scope.
- Existing ships of 24 metres and above are within scope after specified dates, but they may retain then-existing tonnages for the purpose of applying other existing regulations (subject to the exceptions noted).
- Ships under 24 metres may be included depending on registration dates and whether the owner requests determination under earlier acceptable tonnage rules.
- Substantial variations triggered by alterations or modifications can require re-determination.
Section 3(3) also contains a crucial compliance rule: once a Singapore ship has its gross and net tonnages determined under Part II, it must not have those tonnages re-determined unless it is in accordance with the Regulations. This supports stability of tonnage figures for regulatory purposes, while still allowing changes where the Regulations permit.
3) Transitional “interim scheme” for certain ships (s 4)
Section 4 provides an interim measurement approach for certain ships that were at particular construction stages around the transition to the 1969 Convention regime. At the owner’s request, a ship may use gross tonnage determined under tonnage rules acceptable to Singapore prior to 6 September 1985, but only if the ship meets the specified keel-laying / construction-stage conditions.
Practically, the interim scheme is about avoiding immediate re-measurement for qualifying ships, while still ensuring that certificates and documents clearly indicate the basis of measurement. Section 4(2) requires a footnote on the relevant certificates stating that the gross tonnage was measured under rules acceptable to Singapore prior to the coming into force of the 1969 Convention. In the case of certain partial application scenarios (s 4(1)(b)), the entry is limited to a specific certificate (the Cargo Ship Safety Radiotelephony Certificate).
4) Mandatory notification of alterations that may increase tonnage (s 5)
Section 5 imposes an owner’s duty to notify the Director in writing before certain alterations or modifications. The notification requirement applies particularly where:
- a ship is undergoing alteration or modification in construction (including certain ships registered before 6 September 1985); or
- a ship already issued with a tonnage certificate undergoes alterations affecting arrangement, construction, capacity, use of spaces, the total number of passengers permitted, or assigned load line/permitted draught—where such changes would result in an increase in gross or net tonnage.
Section 5(2) provides an enforcement mechanism: failure to comply is an offence, punishable on conviction by a fine not exceeding $2,000. For counsel, the key is to treat tonnage as a living regulatory attribute: modifications can trigger notification duties and potentially re-measurement/certification consequences.
5) Certification process and administrative control (ss 6–10)
Although the extract truncates the text of s 6, the structure is clear. Section 6 governs how an application for determination of tonnages must be made to the Certifying Authority. Section 7 addresses the issue of certificates once tonnage is determined. Section 8 provides for the issuance/recognition of certificates by the government of another Contracting State, reflecting the Convention’s mutual recognition approach.
Section 9 deals with cancellation of certificates, and s 10 provides for inspection. Together, these provisions establish an administrative lifecycle: application → determination → certificate issuance → ongoing oversight (inspection) → possible cancellation where circumstances warrant.
6) Part II measurement rules for gross and net tonnages (ss 11–18)
Part II is the technical core. Section 11 confirms that determination of gross and net tonnages must be in accordance with Part II. Section 12 defines terms used in Part II, and ss 13–16 set out the measurement and calculation methodology, including:
- Measurement and calculation (s 13)
- Calculation of volumes (s 14)
- Gross tonnage (s 15)
- Net tonnage (s 16)
Section 17 addresses the tonnage of segregated ballast tanks, a specialised topic that can affect how certain spaces contribute to tonnage. Section 18 addresses change of net tonnage, which is particularly relevant when a ship’s configuration or operational use changes in a way that affects the net tonnage calculation.
For practitioners, the schedules (including the Second Schedule: Excluded spaces) are often where disputes arise. Excluded spaces can materially affect the computed volumes and therefore the final tonnage figures. Advising on modifications, retrofits, or classification changes will require careful mapping of the vessel’s spaces to the schedule categories.
How Is This Legislation Structured?
The Regulations are organised into two main parts plus schedules:
- Part I: General Provisions (ss 2–10). This part covers definitions, scope (application), transitional arrangements (interim scheme), owner notification duties, and the administrative framework for applications, certificates, recognition, cancellation, and inspection.
- Part II: Regulations for Determining Gross and Net Tonnages of Ships (ss 11–18). This part contains the measurement methodology and rules for calculating gross tonnage, net tonnage, special tank treatment, and changes in net tonnage.
- Schedules (First, Second, Third). These provide detailed lists and technical rules, including excluded spaces that affect tonnage calculations.
Who Does This Legislation Apply To?
The Regulations apply to Singapore ships that fall within the scope set out in s 3. This includes both new ships and existing ships depending on length thresholds, registration dates, and whether substantial variations or specified alterations occur.
In addition to shipowners, the Regulations also affect parties involved in certification and measurement. The Director of Marine is the key authority, and the Certifying Authority includes the Director and other organisations authorised by the Minister. Owners (and their representatives) must engage with the certification process and comply with the notification duties when alterations could increase gross or net tonnage.
Why Is This Legislation Important?
Although tonnage measurement can appear technical, it has direct regulatory consequences. Many maritime regulatory regimes—particularly those tied to safety and operational requirements—use gross and net tonnage as thresholds. If a ship’s tonnage is calculated incorrectly, outdated, or not properly certified, the ship may face compliance problems, delays in approvals, or disputes with regulators and counterparties.
The Regulations are also important because they promote international consistency. By aligning with the 1969 Tonnage Measurement Convention, Singapore ensures that tonnage figures are comparable across jurisdictions. This matters for international trading, port state control interactions, and recognition of certificates issued by other Contracting States under s 8.
From a risk-management perspective, s 5’s notification requirement is a practical compliance lever. Owners and managers should implement internal change-control processes for vessel modifications—especially changes to space arrangements, capacity, passenger numbers, and draught/load line parameters—so that the Director is notified before tonnage increases. Failure to do so is an offence, and even where enforcement is unlikely, the absence of notification can complicate certification and inspection outcomes.
Related Legislation
- Merchant Shipping Act (Cap. 179) (authorising provision: s 392)
- Merchant Shipping (Authorised Organisations) Regulations 1996 (relevant to the definition of Certifying Authority)
- Merchant Shipping (Safety Convention) Regulations (referred to in the interim scheme)
- Merchant Shipping (Non-Convention Ships) Safety Regulations (referred to in the interim scheme)
- International Convention on Tonnage Measurement of Ships, 1969
Source Documents
This article provides an overview of the Merchant Shipping (Tonnage) Regulations for legal research and educational purposes. It does not constitute legal advice. Readers should consult the official text for authoritative provisions.