Clarification of the term 'rigidly connected'

1 Policy Objective

1.1 The objective of this policy is to provide clarification of the term "rigidly connected" as used in the Collision Regulations.

1.2 This will help ensure a common understanding and consistency in the application of the Collision Regulations in the case of a pushing vessel and a vessel being pushed ahead that are "rigidly connected" in a composite unit.

2 Policy Statement

2.1 The term "rigidly connected" in the Collision Regulations means that the connection results in there being no relative motion between the pushing vessel and the vessel being pushed ahead.

3 Scope

3.1 This policy applies to the term "rigidly connected" as used in the Collision Regulations.

4 Authority

4.1 This policy comes under the overall administrative authority of the Marine Executive committee and the Director, Operations and Environmental Programs has approved this policy for general application.

5 Responsibility / further information

5.1 The Director, Operations and Environmental Programs (AMSE) is accountable for this policy whilst the Regional Directors are responsible for the application of this policy.

5.2 The Manager Navigation Safety and Radiocommunications may be contacted at 613-991-3134 should further clarification be required.

6 Related Documents

6.1 Collision Regulations.

6.2 Discussion paper - Clarification of the term "rigidly connected in a composite unit" - RDIMS # 6989550.

6.3 CMAC Presentations: RDIMS # 7027107E / 7042620F and Minutes # 7136630.

7 Background

7.1 Collision Regulations Rule 24(b) requires that when a pushing vessel and vessel being pushed ahead are rigidly connected in a composite unit they shall be regarded as a single power-driven vessel and exhibit the lights prescribed in Rule 23 (Power-driven Vessel Underway). Rule 35 (Sound Signals in Restricted Visibility) also requires a pushing vessel and vessel being pushed ahead that are rigidly connected in a composite unit to sound the same signals as a single power-driven vessel and not the signal of a vessel engaged in towing or pushing another vessel.

7.2 There is a wide variety of connection methods used for tug and barge pushing operations, ranging from simple to very complex systems. Almost all are designed to allow some relative movement between the tug and the barge i.e., independent pitching. Until now, there has been no agreement on the interpretation of "rigidly connected in a composite unit" and therefore which lights are supposed to be exhibited by a vessel pushing another vessel. Without a common understanding, the navigation lights exhibited by vessel engaged in pushing operations will continue to be inconsistent.

7.3 This issue was highlighted several years ago by the Marine Safety Tug and Barge Working Group, which was formed to examine the overall status of tug and barge operations and regulations in Canada. This working group reported in 2005, among other things, "It is recommended by the WG that a common definition of terms be used nationally. Such terms as articulated, integrated, combination, rigidly connected etc has led to misunderstandings and confusion."

7.4 From 2006 to 2011, this issue has been discussed at length at several CMAC meetings including the Tug and Barge Working Group. Based on consultations with towing representatives, Marine Safety presented the proposed interpretation at the November 2011 National CMAC meeting in the Tug and Barge Working Group and the Standing Committee on Navigation and Operations. The proposed interpretation was supported and no dissenting views were expressed.

8 Date of Application

8.1 This policy becomes effective on May 4, 2012.

9 Date for Review or Expiry

9.1 This policy shall be in effect until rescinded.

10 RDIMS Reference

10.1 The English version of this document is saved in RDIMS # 7380861.

10.2 This is the first approved and finalized revision of the English version of this document.

10.3 La version française du présent document est dans le SGDDI # 7425979.

10.4 Il s'agit de la première révision a approuvé et finalisé de la version anglaise de ce document.

11 Keywords

  • Rigidly Connected
  • Composite Unit
  • Tug and Barge
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