By Allan Leth, , Alimak AB
SubscribeContainer ports around the world are under increasing pressure to increase TEUs handling capacity and to accept and turn round ships more quickly.
The owners of the new mega- container vessels are also anxious to see their ships berthed for the shortest possible time.
Port operators, therefore, need to consider any opportunity to increase the number of moves per hour for each crane. One way to do this is to reduce inevitable unscheduled downtime periods to a minimum.
ALIMAK SE access lifts enable faster service times, which means more uptime. It has been claimed that these lifts reduce crane maintenance and downtime by as much as 25%
In the past, arguments for providing access lifts on container cranes have been on health, safety and convenience. As important as these are, it has greater significance for operators when the economic benefits are also taken into consideration.
All container ports are conscious of costs and subscribe to the principle that ‘Time is Money’. Future indications show that the pressure on time is going to increase significantly, thereby placing an ever-increasing emphasis on equipment service and maintenance.
Greater throughput, larger vessels and associated infrastructure developments will put port management under increasing pressure to turn ships round more quickly and process container forwarding at a faster rate. Operating efficiency will become even more critical especially as mega-ships holding over 6,000 TEUs will expect a service-window of 48 hours.
A consequence of this, will inevitably be trying to maximise on the theoretical output of 35 to 40 moves per hour or more for most container gantry cranes. Reports indicated that typically this is 20 to 25.
Double-trolley gantry cranes are intended to reach 50 TEUs per hour per hold. i.e. almost double the usual output.
The downside to increasing productivity from container cranes will be a growing tendency to reduce preventive maintenance procedure in order to create more uptime. The combination of these two factors must lead to an increase in unscheduled downtime, which is significantly more costly than scheduled downtime.
Improved Access Shortens Downtime
Downtime, scheduled and unscheduled, is unavoidable, but facilitating faster, easier servicing can reduce the impact and costs of downtime.
Container crane access lifts such as the ALIMAK SE are an extremely cost-efficient means of reducing service time by enabling faster, safer access during downtime.
Allan Leth, Segment Manager - Container Cranes at Alimak AB ;
“Many port authorities specify Alimak access lifts to be fitted as standard when ordering container cranes. Alimak lifts are based on rack and pinion drive technology - a technology proven over more than 40 years. It is the most reliable, durable and efficient system, particularly in the harsh environmental conditions of ports.
Most servicing on container cranes is at height, therefore, providing maintenance engineers with a faster means of access, and the facility to transport payloads up to 600 kg at speeds of 0.8 m/s means that all downtime time is reduced. Typically as little as 1-minute from bottom to top in a lift compared to 15 to 20 exhausting minutes by ladder, stairs and walkways – possibly longer when carrying service tools and components.”
Easy Retrofitting
Today, most new orders for container cranes do specify access lifts because of the recognized cost and time benefits.
However, container gantry cranes, with costs often exceeding $5 million, have to be a long-term investment but the older a crane becomes so there is a proportional rise in the downtime. So there is still a high population of older container cranes, which have either no access lift or an access solution that is inefficient.
The ALIMAK SE is extremely easy to retrofit to existing container cranes. This can be done during modernisation or extensive servicing, as it requires only a few days.
Rack and pinion drive significantly reduces the amount of modification required to the crane itself. Alimak access lift can be retrofitted to all cranes – even models with angled or inclined legs, in which case the care frame is modified to compensate.
No Compromise
Alimak lifts require no compromise from crane operators. They meet all statutory regulations, nationally and
Allan Leth ;
“Unscheduled downtimes on container gantry cranes are usually for short periods of time. This means that the time spent gaining access per downtime period is more significant, making an efficient access solution significantly more important.
To ensure that Alimak access lifts provide the optimum solution, we work in partnership with Ports and Harbour Authorities as well as container crane manufacturers. This close relationship also benefits research and development by making us more aware of the problems in installation and operation, we also recognize that different operators have different requirements. This is why the ALIMAK SE lift concept offers an extensive choice of over 30 car sizes, lifting capacities from 300 kg to 2400 kg, various travel speeds, and other options and add-ons.”
Options include cars and landing cabins fabricated from stainless steel panels to give protection from the corrosive environments, emergency flashing lights on the car roof, automatic return of the car to the bottom landing after a pre-set time, heater in the electric cabinet, automatic rack lubricator and a fire extinguisher.
Other benefits of Alimak access lifts are:
- They are completely self-contained units.
- There is no requirement for a machine room, as they carry the drive units.
- Modular design means they can be extremely compact and are the ideal solution where space is limited.
- They do not add a significant amount of load to the crane
- They are designed to minimise additional wind loading on the crane.
- In the event of a power failure, they are easily and safely, lowered to the ground.
Leaders in Vertical Access Technology
To date, more than 1700 Alimak access lifts have been installed on container cranes around the world, they are the first choice for many container crane operators. For example, at Singapore port where there are over 250 Alimak lifts, and in terminals, large and small, in over 50 countries for ship to shore cranes as well as RTGs and RMGs.
Conclusion
Given their comparatively low cost (as part of a total container crane package), access lifts, such as the ALIMAK SE, for container cranes do contribute to operating cost efficiencies.
Allan Leth in summing up:
“Experience shows that the installation of access lifts has resulted in more efficient maintenance and, as a result, less downtime. Additional savings are realized because tools and exchange parts are carried in the lift car, thus eliminating waiting time. It has also been possible to reduce breakdowns appreciably as the lift has facilitated preventive maintenance.
A leading shipping company claims that our lifts have reduced crane maintenance and downtime by as much as 25%.
Without a lift, maintenance personnel and crane operators have to climb ladders. To get to the top of an ordinary container crane takes some 15–20 minutes of hard work, which does not encourage frequent maintenance and inspection. Moreover, parts and tools required for repairs and exchange have to be lifted by means of winches or other such devices. These are all time consuming operations.”
And, as everyone in container port management appreciates – time is money.