Before shock absorbers and heave compensators became available for use in offshore lifting, every offshore lift could pose a risk. Overload damage, dynamic shock loads, and rough weather could mean costly delays, equipment stress, and safety concerns. Cranemaster (formerly Ernst B. Johansen AS) changed that. Back in 1987, together with BP Norway Ltd. Cranemaster tested its shock absorbers in harsh North Sea conditions.
Rigorous Testing and Certification
In the 1980s, offshore lifting under dynamic conditions meant risking overload damage from shock loads, unpredictable crane behaviour, and frequent operational shutdowns due to rough weather. Equipment damage, safety incidents, and costly downtime were not outliers—they were expected.
Cranemaster—then known as Ernst B. Johansen AS—set out to eliminate that risk. For years, the company had been developing advanced solutions in passive heave compensation and energy absorption. But the turning point came in 1987, when Cranemaster partnered with BP Norway Ltd. for a groundbreaking offshore field test.
The mission: to deploy a 15-tonne shock absorber in the unforgiving ULA Field of the North Sea, and prove—under real-world conditions—that dynamic loads could be controlled and absorbed without compromising safety or efficiency.
Used for topside lift between platform and vessel /vessel to platform.
The results exceeded expectations.
Cranemaster’s shock absorber demonstrated consistent, high-performance load control in harsh conditions. It neutralized shock forces, stabilized crane operations, and enabled precise lifts even in rough seas. This wasn’t just an operational improvement—it was a redefinition of what was possible in offshore lifting.
The technology’s performance earned it Type Approval from both Det Norske Veritas (DnV) and Lloyd’s Register. But more importantly, it prompted DNV, Lloyd’s, ABS, BV and others to introduce a new industry procedure for re-rating cranes and calculating load charts for systems using Cranemaster technology. It wasn’t just accepted—it changed the rules.
Cranemaster had done more than deliver a technical innovation. It had made offshore lifting safer, more efficient, and less dependent on weather constraints. The technology allowed for heavier lifts, extended weather windows, and greater operational confidence—transforming offshore lifting from a high-risk activity into a controlled, calculated operation.
Cranemaster’s shock absorber became a benchmark for a new era of offshore safety and performance.
We’ve been lifting safer for over 40 years.
When Cranemaster’s Ernst B. Johansen first brought shock absorbers to offshore lifting, the goal was simple: reduce risk and increase weather windows. That mission hasn't changed—but the challenges certainly have.
Today, offshore operations demand more: higher loads, deeper waters, tighter weather windows. And Cranemaster has evolved with every wave of change.
From our original CM1 unit—still reliably operating decades later—to today’s advanced CM3 systems featuring the integrated CMAC control system that adjusts damping properties throughout each phase of installation, Cranemaster continues to push the boundaries of offshore lifting performance.
