The market for containerised bulk handling systems is getting more sophisticated as suppliers develop more options for using standard ISO containers as well as special bulk boxes in the supply chain.
A well established manufacturer and designer, Container Rotation Systems (CRS) builds its Rotainer line of container rotating systems in Australia, and works with Chinese container manufacturers to supply special bulk containers and lid systems.
This year, the company is celebrating its 10th anniversary, and its Rotainer container tippler has continued to evolve over that period. Speaking with Bulk Materials International, CRS management said the first Rotainers were built for handling very heavy iron ore in Australia. The customers were new to the whole concept of rotating containers to unload bulk materials, and the emphasis was on engineering a product that would stand up to the duty cycle.
The first Rotainer HDs (heavyduty) were therefore developed to be “the biggest and the strongest” for these applications, and their reliability has been proven in the field, according to CRS. For example, two units delivered five years ago to Nevsun Resources’ Bisha Copper Mine expansion project in Eritrea, where they are used to load copper concentrate at the port of Massawa, have just been surveyed by CRS and approved for use for another five years.
Taking the product global has led CRS to come up with a new design that is better suited for the European market and can cater for heavy applications up to 42t. While coal, for example, weighs around 1,000-1,350kg per m3 , cargo such as woodchips weighs closer to 350 kg per m3 and can be more effectively loaded from 40ft containers.
CRS’s latest product is its lightweight Eurospec 32 40ft Rotainer, which is designed to handle its Rotorcon 40ft bulk containers. These are available in 2,400mm, 2,600mm and 2,900mm (high cube) height variations. At 2,900mm high, the tare weight is 6,500 kg, and the maximum gross weight loaded is 34.5t. The containers have no internal cross bracing, are fully certified for 180 and 360 degree rotation, and also carry CSC certification. They are available with or without lids and automatic lid locks, and with an end-door for tipping-unloading as an option.
The matching Rotainer is the new CRS Eurospec 32 model, which is available with or without a lidlifting system. This features a single beam design that CRS believes will become an industry benchmark. With a single beam and other changes CRS has been able to reduce the tare weight of its design by around 3t. A 38t version is also available for a larger load capacity.
As well as more Rotainer options, CRS is coming up with ways to increase the pool of special bulk boxes available to customers that want to use the Rotainer unloading concept. One customer, Townsville Marine Logistics, is using a Rotainer to handle zinc concentrate at Townsville port, and it needs over 1,000 half-height containers to support the system. In Australia, these could be leased from Cronos, which has supplied several mining projects with half-height boxes in recent years. To give its customers more options CRS has developed a conversion kit that adds an automatic lid-locking system to locally available Seaco half-height containers. CRS says that this opens up another 20,000-30,000 half-heights globally to the pool that can be used for rotating applications.
CRS now offers rental equipment in Australia, and has recently supplied a Rotainer with a lid-locking system for a construction project in Darling Harbour, Sydney. There, half-height containers are loaded underground with construction spoil, sealed with a lid, and then loaded onto trucks using an overhead crane with a CRS fixed frame spreader suspended on chains. Once sealed, the containers can be safely transported through Sydney to a disposal site, where they are unloaded with a Rotainer.
RAM crosses 100
RAM Spreaders also has a container tippler in its lineup, the RAM Revolver, and chief sales officer Cameron Hay says it now has over 120 units in service around the world. These include 40ft units, of which RAM has now delivered three, including a 55t capacity design for a client loading sugar. However, RAM has found that 40ft units are more suited to STS cranes than mobile harbour cranes due to the hatch sizes of bulk vessels.
Hay is passionate about the potential for containerised bulk handling (CBH) systems, where he says much of RAM’s success is due to its flexible approach to individually engineering a system for each customer’s requirements. And there is still plenty of potential in the market – a CBH system will never be able to match the economies of scale of a conveyor based loading system for high-volume operations, but it is a much faster and cheaper way to enter the bulk handling business at existing ports. Hay asserts, however, that CBH systems are not just for low-volume operations, and RAM’s customers using its Revolvers continue to push the envelope when it comes to shiploading rates and annual throughputs.
As an example, Hay cites Puerto Angamos in Chile. Using the RAM Revolver, Puerto Angamos was able to start handling copper concentrate in small quantities in 2014. By 2018, it had handled 2 Mt of the cargo, and is now using the Revolver system to handle other types of cargo.
In Adelaide, Australia, IMX Resources reached 2 Mtpa within two years of commencing iron ore exports, before its Cairn Hill mine was closed in 2014. Others are planning for 8 Mtpa, which Hay said is “easily available” as one standard 40t capacity STS crane can support a loading rate of 1,200 tph. “The key to this is fast landing, which Revolver achieves with its ‘reverse bathtub’ design for landing on the box,” explained Hay. For faster loading rates, RAM also offers a 55t Revolver.
Talking about the growing customer base, Hay said the Revolver CBH system tends to appeal to two main groups. One is “enviro-driven” operators that would not get approval to handle loose bulk materials, or are handling very valuable commodities where any losses are unacceptable. The second group are customers using Revolvers at locations where there are no bulk facilities, or where existing multipurpose terminals have low berth occupancy. This is particularly the case in developing countries like the Democratic Republic of the Congo, Mauritania and Togo.
For enviro-driven customers handling valuable commodities, a CBH system has the advantage of minimal product loss. A container of copper concentrate containing some gold and silver deposits can be worth US$100,000, and “material loss is king” when it comes to the handling process in this case, stressed Hay. “Most systems lose 2-3% in the logistics chain, with best practice at 0.5%,” he said. At a copper price of US$2,000/t, a 0.5% loss over an annual production of 400,000t represents considerable value. With a CBH system, the container is sealed at the mine, and is only opened at the bottom of the hatch under a fogging curtain that suppresses dust, which achieves a zero loss rate.
On the environmental side, a properly implemented CBH system can eliminate dust in transport in the supply chain and at vessel loading. Dust is a major factor at Port Elizabeth in South Africa, where RAM first delivered a Revolver five years ago. Port Elizabeth handles manganese ore, and has increased this business significantly. Port operator Transnet is now handling over 5 Mtpa of manganese ore, and recently took delivery of four more Revolvers.
The port is under pressure from the local community over fugitive dust from its operation. To protect the environment during vessel loading, a misting system is used at the hatch covers, and the amount of dust generated during the unloading cycle is minimised by tipping the load at the bottom of the hatch. This, says RAM, results in “zero fugitive dust emissions”.
However, this is only at the loading point, and Port Elizabeth can stockpile up to 25,000t of the ore, which is the main source of fugitive dust. For some time now, Transnet has been considering moving some or all of this business to Ngqura in the Eastern Cape or another location.
As CBH systems mature, other equipment suppliers are paying more attention to how container tipplers can work with existing equipment. A lot of RAM Revolvers are used with mobile harbour cranes, and RAM has worked closely with Liebherr to develop a separate load curve for Revolvers, which sits in between the load curve for a grab and a spreader. While mobile harbour cranes for dedicated grab operations are sometimes built to a higher fatigue classification than for container operations, a Revolver does not require this, said Hay.
While the Revolver unloads a bulk container and most CBH applications are centred on export materials, there are also opportunities on the import side of bulk cargo logistics, using the CBH concept to load boxes at a port and move the cargo inland. Since 2014, RAM has been part of the SMAG group, which manufactures grabs and other attachments. SMAG and RAM are now looking to combine their offerings to deliver all “attachments under the hook”.
Hay said the idea of CBH systems for import cargo is gaining popularity, and RAM has delivered in six projects to date. One is an import project in Bolivia, where the cargo is unloaded at the port with a SMAG grab, and offloaded inland with a Revolver on a reach stacker.
As popular as container rotators have become, one drawback of these systems is that they require dedicated bulk containers. Other companies want to take advantage of the standard ISO containers that are being shipped empty, to carry bulk cargo at a lower cost.
To facilitate this, CRS is now building its patentpending Tiltainer system, a prototype container tipping attachment that can tilt a container endwise by a full 90 degrees. While other such units tilt boxes up to 60 degrees, CRS said experience shows that this is not enough to get all the material out of the box, and this led CRS to develop a 90-degree tilting system.
The unit connects to a container spreader and has a 3m CoG adjustment in the tilting mechanism that is electronically controlled to manage the unloading speed. A spreader attachment reduces the available load capacity, but by keeping the weight of its design to 7t, CRS believes it is able to deliver sufficient load capacity with a 45t crane or a mobile machine, such as a reach stacker.
RAM is also developing a container tilting system for free-flowing bulk materials. This will target both the full export process and opportunities for moving bulk cargo, as well as scrap, tyres and other products that can be tipped out of a container, from inland locations to a port for loading with other equipment.
In consultation with Liebherr, RAM has now developed a tilting spreader for a customer, and the first units are on order. Hay added that while using standard containers eliminates the need for specialised bulk units, the unloading process is less efficient and slower than a dedicated bulk container and a RAM Revolver.