The engine order telegraph is the mechanical or electro-hydraulic link between the bridge command and the engine room order. On a straight-through mechanical telegraph the two positions are physically linked; on a remote telegraph the order is transmitted electrically or pneumatically and the two ends must be proven to agree. That difference decides the whole test method, so the arrangement has to be identified before anything is proved.
Key facts and acceptance criteria
The table below lists the values that decide whether the system passes at survey and at maintenance. They come from the maker documentation and the applicable rules, not from general practice, and they are the numbers a surveyor checks.
| Parameter | Requirement | Reference |
|---|---|---|
| Command agreement | Bridge and engine room order must agree at all times | SOLAS V/34 |
| Telegraph follow-up | Engine speed must follow the commanded position | Maker technical manual |
| Astern interlocking | Astern command inhibited while ahead running | SOLAS II-1/26 and maker procedure |
| Position indication | Both ends must show the same order | SOLAS V/34 |
| Mechanical telegraph | Both handles physically interlocked | Maker technical manual |
Regulatory and technical basis
SOLAS Chapter V regulation 34, SOLAS Chapter II-1 regulation 26 for the safety devices the telegraph circuit may carry, and the maker technical manual. Telegraph follow-up, astern interlocking and remote position indication are normally confirmed at the annual survey.
What the service assessment covers
Seanav Marine provides independent service assessment. The following items define a starting scope for a competent service assessment. The actual test method and acceptance criteria come from the installed equipment documentation and the agreed job scope.
- Bridge and engine room order agreement, follow-up and position indication testing
- Astern command, crash astern and astern interlocking verification
- Chase, interlock and detent mechanism inspection on mechanical telegraphs
- Hydraulic and electrical remote telegraph circuit testing and leakage checks
- Position feedback, telemetry and alarm fault diagnosis
How the work is planned and executed
- Identify the arrangement. Establish whether the installation is a mechanical chase, a hydraulic remote or an electro-mechanical remote, and obtain the maker procedure for that variant.
- Visual and mechanical check. Inspect the chase, linkage, detents, oil levels and interlock mechanisms, and confirm the grips and handles are sound.
- Functional test. Prove order agreement, follow-up, astern operation and the interlocks from every telegraph position, with the engine running where the procedure requires it.
- Record. Issue the test record with the positions proved, the conditions of the test and any defects raised for the maker or the vessel.
Failures that must be distinguished before testing
Do not widen a setpoint or suppress an indication without an engineering assessment. The following failure modes have to be separated from a genuine plant fault before a conclusion is drawn, because they are common, they are visible, and they are usually the cheaper explanation.
- Mechanical chase wear that allows the bridge and engine room handles to disagree under heavy weather motion
- Hydraulic remote telegraphs that lose the order under a pressure leak in the charging circuit
- Astern interlocks that are defeated by a temporary bypass left in place after a repair
Equipment and OEM compatibility
Replacement parts and calibration methods must come from the original manufacturer. Seanav Marine works with Kongsberg bridge and engine control telegraphs, Woodward and Kongsberg telegraphs, Siemens and ABB remote telegraph systems, and maker-specific electro-hydraulic chassis. and sources parts through authorised distributor channels.
Frequently asked questions
How do I know if the telegraph is mechanical or remote?
A mechanical telegraph has a physical chase and interlocking handle between the bridge and the engine room. A remote telegraph transmits the order electrically, pneumatically or by another means and shows position at each end. The maker plate and the drawing set confirm which is fitted.
Why does the engine room order sometimes disagree with the bridge?
Usually a mechanical chase or detent problem on a mechanical unit, or a pressure leak, sensor or feedback fault on a remote unit. The arrangement has to be identified before the cause can be isolated.
Is astern operation tested with the engine running?
The maker procedure decides the test conditions and the sequence, including whether a full ahead-to-astern test is permitted. Some telegraphs are subject to a maker speed limitation or a written procedure for testing astern.
What is included in a telegraph service report?
The arrangement identified, the positions and functions proved, the as-found condition, any defects and the parts used, against the maker procedure.
Reference framework
These sources explain the relevant system or regulatory context. They do not replace the installed equipment manual or prove the applicability of a particular rule to every vessel.
service@seanav.org · +971 58 568 1197 · Contact the operations desk
About this guide
Published by Seanav Marine. Editorial and source review: . This general service guide is based on the references shown; it is not a signed vessel-specific engineering procedure. Equipment manuals and the responsible technical personnel determine the job requirements.
For technical assessment or a factual correction, contact Seanav Marine with the equipment identity and supporting documents.