Every SOLAS-classed boat has lifeboats based on one unavoidable guarantee: the engine has to start when there is no other option. The promise is contained in SOLAS Chapter III and detailed in the LSA Code, covering everything from the flashpoint of fuel to cold weather starting performance. However, in reality, this is the most frequently made clear in drills — not because the regulations are unclear, but rather because beginning systems are prone to degradation during inspections. We explain the exact requirements SOLAS along with the LSA Code require for lifeboat engines, highlighting where the majority of ship owners fail in compliance, and how a safe ready for drills appears to be.

Where the Requirements Come From: SOLAS Chapter III & the LSA Code

SOLAS Chapter III sets the legal framework for life-saving equipment, and the specifics of engineering for propulsion of lifeboats are contained within the LSA Code, specifically under section 4.4.6 which regulates lifeboat propulsion. Classification societies and flag states rely on this section as their technical base when approving construction, annual maintenance and Port State Control inspections. It’s less about reciting regulation numbers and more about understanding what five or six of the requirements are actually being scrutinized.

Core SOLAS/LSA Code Requirements for Lifeboat Engines

Engine Type & Fuel

Every lifeboat engine must be a compression ignition (diesel) type, and no engine may be used if its fuel has a flashpoint of 43°C or less, tested by the closed cup method. This rules out gasoline-fuelled engines entirely — a spark-ignition system introduces fire risk in exactly the emergency scenario a lifeboat is meant to survive.

Cold-Start Performance

This is the requirement that separates a compliant engine from a merely functional one. Starting systems and starting aids must be able to start the engine at an ambient temperature of -15°C within two minutes of beginning the start procedure, unless the administration approves a different temperature based on the ship’s trading routes. For vessels operating in cold climates, this single line drives most of the engineering decisions behind the starting system.

Starting System Requirements

The engine must be fitted with either a manual starting system or a power starting system backed by two independent rechargeable energy sources, along with any necessary starting aids. A detail many ship owners overlook: radio batteries are explicitly prohibited from being used to power engine starting — the two systems must stay electrically isolated so a communications failure never compounds a propulsion failure.

Operation Under Emergency Conditions

Compliance doesn’t end once the engine fires. The engine has to be able to operate up to five minutes following an initial cold start, when the lifeboat is out of the water. Additionally, it should be able of operating regardless of whether the lifeboat is filled to the waterline, a situation that is a realistic launch scenario with the midst of heavy oceans.

Accessibility

The engine’s starting system must not be hindered by the engine casing seating, or any other fittings, so that the crew are able to operate it with no delay during high-stress launches.

Why Starting Reliability Is the Requirement Ship Owners Struggle With Most

Read on paper, these requirements look straightforward. In service, they collide with a physical reality: salt air, humidity, vibration, and long stretches of idle time are exactly the conditions that degrade rechargeable batteries. A battery-based starting system that passes inspection in dry dock can lose enough capacity within months at sea to miss the -15°C, two-minute window entirely — and because lifeboat drills happen only monthly, that degradation often goes unnoticed until it matters most. This gap between “compliant on paper” and “reliable in practice” is precisely why starting failures remain one of the most frequently cited deficiencies during lifeboat drills and Port State Control checks, a pattern we examined in more operational detail in 9 Common Reasons for Ship’s Lifeboat Engine Starting Failure.

Manual Starting Systems: A Compliance-Ready Backup Worth Reconsidering

It’s worth remembering that the LSA Code never mandates batteries — it explicitly permits a manual starting system as a standalone compliant option, not a fallback of last resort. This is where a mechanical spring starter earns its place on a lifeboat. Instead of storing energy chemically in a battery, it stores mechanical energy in a pre-tensioned spring, releasing it instantly to crank the engine. There’s no charge cycle to maintain, no corrosion-prone terminals, and no capacity loss from cold or salt exposure — the stored energy is either there or it isn’t, and it doesn’t fade with time the way battery charge does. That makes it naturally suited to the -15°C, two-minute standard the LSA Code sets, and to the two-independent-source logic behind the regulation: a spring starter paired with a battery system gives a lifeboat two genuinely different failure modes to guard against, rather than two batteries that can degrade for the same underlying reasons. You can see the full range of configurations on our Spring Starter.

Inspection & Maintenance Obligations Ship Owners Can’t Skip

Lifeboat engines require a monthly inspection of the hull, release gear, and engine, along with annual servicing by an approved lifeboat service provider, on top of the routine launch drills required every three months. Crucially, these checks should test the starting system on its own — not just confirm the engine eventually runs — since a slow or hesitant start is often the earliest sign of a failing battery long before total failure occurs.

Compliance Checklist for Ship Owners & DPAs

  • ☐ Confirm the engine starts within 2 minutes at -15°C ambient
  • ☐ Verify two independent starting energy sources are fitted and isolated from radio power
  • ☐ Test the manual starting system independently during drills, not only as backup
  • ☐ Confirm the starting system remains unobstructed by casing or seating
  • ☐ Log starting time and any hesitation during every monthly drill
  • ☐ Schedule annual servicing with an approved provider before certificate renewal

Frequently Asked Questions

Not necessarily two batteries specifically — the LSA Code requires either a manual starting system or a power system with two independent rechargeable sources, and batteries are the most common but not the only way to meet that standard.

Yes. A manual starting system is a fully compliant option under the LSA Code, not merely a backup for when power starting fails.

Monthly drills should include an operational test of the starting system, with more thorough servicing performed annually by an approved provider.

Meeting SOLAS lifeboat engine requirements isn’t about having a starting system that technically satisfies the checklist — it’s about having one that still performs exactly the same way after months at sea, in the cold, under salt spray, with no warning before it’s needed. Reviewing how your current starting system holds up against that standard, and where a mechanical alternative could close the gap, is worth doing before the next inspection finds it for you.