The genesis of the carriage of refrigerated cargoes began around the middle of the 19th century towards the end of the Industrial Revolution when the bulk of the working population had moved from the countryside into large cities that had grown up around the factories principally in the midlands.
This new urban population required meat and cereals to sustain the work force and counteract the effects of malnutrition which[ds_preview] was prevalent among the migrants. This drift of the population from the countryside more or less coincided with the growing production of agricultural produce in Australia and South America where farmers had actively begun to pursue ways of shipping their growing surpluses to Europe.
Many attempts were made to develop ways of preserving meat over long distances. It was not until the last quarter of the 19th that refrigerated cargoes of meat were successfully transported from the Argentine to France. The last part of the 19th century witnessed a period of great experimentation in the development of refrigerating machinery principally for the carriage of beef and mutton. Successful experiments were also carried out with the transport of chilled cargoes from the USA to Britain. This particular form of transport would also prove to be of great interest to fruit growers and exporters.
In 1901 four passenger / mail-ships were built for the Imperial Direct West Indian Mail Service for the trade between Avonmouth and Kingston. The 14 knot ships had accommodation for about 150 passengers and about 5,000 ton of cargo. The return fare to Jamaica was 32. These ships were especially notable as they were equipped to carry refrigerated cargoes. Elders and Fyffes shipped their first commercial cargo of bananas to Britain in one of these ships called the S. S. »Port Morant«. At the turn of the last century owners were very conscious of the importance of earning revenue on each leg of a voyage. This is the same problem facing owners / operators of refrigerated cargo liners who are faced with the replacement of an ageing fleet. It is no longer possible to operate conventional refrigerated cargo liners in an economical manner with cargoes in on direction where ships may spend up to 50 % of their lives on ballast passages.
During the first half of the 20th century refrigerated cargo liners were generally owned and operated by producers and distributors of their produce. Cargo liners also carried refrigerated cargoes on regular routes.
Speculators entered the transportation sector of the refrigerated cargo business in the latter half of the last century when the shipbuilding boom was being fueled by the availability of finance, generous tax allowances and subsidies.
As these independently owned ships entered the market shippers took advantage of and became dependant upon them to cover fluctuating demands of their business. In the intervening years charter rates failed to generate reasonable returns that would induce speculative owners to reinvest in conventional refrigerated cargo liners. Consequently many of these owners have already decided to withdraw from this sector of the market.
An analysis of the age of the existing fleets of refrigerated cargo liners clearly illustrate the effect that over building during boom years has had on this sector of the market. Around 448 ships are over 20 years of age of which 257 are more than 25 years old.
Whilst the refrigerated cargo trade has benefited from the availability of cheap tonnage it would appear that this state of affairs is unlikely to continue as independent owners are unlikely to invest in this type of ship in the future.
Many shippers prefer to ship their produce in conventional refrigerated cargo liners as it is geared to the logistics of their business. Independent refrigerated cargo liner owners shall only invest in multipurpose ships which will allow them to maximise a return on equity by having the ability to carry cargo on all legs of the voyage.
In future shippers will have to face up to the full cost of providing refrigerated cargo liner tonnage.
At the beginning of the last century owners were very conscious of the importance of earning revenue on each leg of a voyage. This is the same problem facing owner / operators of refrigerated cargo liners today now faced with the replacement of an ageing fleet. It is no longer possible to operate conventional refrigerated cargo ships in an economical manner with cargoes in one direction where the ship spends extended periods of their lives on ballast voyages.
Owners now have the opportunity to invest in multipurpose refrigerated cargo liners, known as »refrigerated palletised container carriers« (RPCC) which can be profitably traded on all sea passages of a voyage. The managers of these ships will need to develop skills that will ensure that the owners may maximise the return on their investments.
Refrigerated cargoes have traditionally been carried in purpose built insulated multideck cargo liners prior to the introduction of the blown air system introduced in the mid 60s in the first large cellular refrigerated cargo liners built for Overseas Containers Ltd. for the Consortias’s Australian-Europe refrigerated cargo trade. The cargo outturn during the 25 year life of the ships was excellent. When these ships became due for replacement a variant of the blown air System was devised which did not require a coupling between the supply of cold air which is cooled with brine from a central cooling plant in the engine room. The system was carefully developed in conjunction with the IHI Marine United Inc.
Traditional refrigerated ship owners are faced with the problem of replacing their ageing fleet and growing competition from owners who now have the capability of carrying large volumes of refrigerated cargoes in integral containers. These owners do not appear to have fully considered the fruit growers preference carriage of containers on deck in addition to palletised cargo in ships’ holds. Such a multipurpose ship gives the charterer an opportunity to maximise its earning capacity on all legs of a voyage.
Traditional refrigerate ship operators have stated that their ships spend as much as half of their lives on ballast voyages. They have also realised that they have a problem of replacing their ageing fleet and are now running the risk of losing control of their business into the hands of containership owners.
This was an ideal moment to revise the RPCC design as a replacement for the traditional refrigerate cargo liner of around 500,000 to 600,000 cu.ft. capacity. All the design and development work has been completed together with cooling down trials carried out in a fruit packing station in California.
The RPCC system has been designed to use ammonia (NH3) as a primary refrigerant. This gas is eco-friendly and requires less power than CFN gases currently being used in all integral containers. The lower power requirements of the RPCC ammonia system makes a significant contribution to the reduction in CO2 emissions thus making the RPCC ideally suited for incorporation in any »Green Ship Project«. Clearly this was the opportune moment to develop a design for a ship that would incorporate the best features of a conventional refrigerate cargo liners and a containership which is not only technically sound but gives an owner an opportunity to retain control of their current business. Any new system must be competitive with existing systems. With this aim in mind the design for the refrigerated palletised container carrier was developed.
Operators of large refrigerate cargo liners have advised that hot spots in the cargo have been costing insurers as much as 7 % of the value of the cargo in claims. The frequent handling of the pallets with fork lift trucks also increases the risk of damage to the cargo.
The RPCC is suitable for the carriage of containers of all types when not engaged in the carriage of refrigerated cargoes. The RPCC is eminently suitable for back haul cargoes such as medicines, wines, luxury goods and films in RPCC containers as well as cross trading opportunity with cargo to way ports thus increasing the earning potential of the ship.
The RPCC design consists of air coolers installed in a plenum chamber arranged to one end of each hold. Air is delivered through a nozzle into a diffuser in each container. There are no mechanical connections between the air supply nozzle and the container. The air coolers are circulated with brine from a central cooling plant in the engine room. Ammonia is the primary refrigerant. Air change facilities are provided in each plenum chamber. The RPCC diffuser was tested in the Sunkist cold store in Port Hueneme in California where the air temperature was held at a steady temperature of 2 °C. by means of a forced ventilation system through air coolers. The test equipment was placed in an empty part of the store which enabled unobstructed work during the whole test period. The cargo tested was Sunkist lemons delivered directly from the grower at a temperature of 15 to 20 °C. Test consisted of monitoring the fruit pulp temperature to determine temperature gradients within the cargo as well as the cooling down rate of 90 changes per hour. Comprehensive test details were logged and the following principal results were noted:
A. Air diffuser performed exactly as predicted in the laboratory tests.
B. Temperature gradients and cooling down rates were better than the cooling down rates achieved on many conventional reefer ships carrying palletised fruit.
C. As expected the worst results were obtained at the far end from the air supply, however the temperature gradient as well as cooling down rate performance were better than for the worst locations on a conventional refrigerated cargo ship. Smoke tests proved fairly even distribution of air through the whole cargo. Full details of these trials are available for analysis.
It should be noted that the RPCC can be built economically compared to a ship designed to carry integral refrigerated container, since the additional equivalent would only consist of the cooling system and the insulation if required, whereas there will be a greater saving of electric generating capacity as well as container box costs. In addition the daily operating costs of the RPCC is significantly lower. For comparison purposes a geared cellular containership having a nominal capacity of about 1312 teu and having the following principal dimensions would be a suitable ship for both a containership capable of carrying 302 x 40’ x 8’ 6” integral containers in the holds or 302 x 40’ x 8’ 6” refrigerated palletised containers in holds. Both versions of the basic design would also have 150 plugs on deck for integral containers.
An analysis of the cost of providing power and the cost of running a generator on heavy fuel, lub.oil, spares and servicing for an RPCC ship is about half of the cost of an equivalent vessel designed to carry integral containers.
The cost of the generating plant and power plugs for an integral refrigerated cargo liner is about half of the cost of the generating and refrigerating plant installed in the RPCC ship.
The integral refrigerated ship and the RPCC will both require a minimum of two sets of consideration. When the cost of the containers are taken into consideration the capital cost of an RPCC ship is about 77 % of the cost of the equivalent integral refrigerated containership.
The cost of hiring an integral container is about $ 12 per day. The cost of hiring two sets of containers could amount to $ 2,645,000. Integral refrigerated containers incur additional charges in the form of Pre Trip Inspection costs every time they carry refrigerated cargo. Each Pre Trip Inspection (PTI) costs about $ 100. If each container is used three times per year the annual cost of a PTI could amount to $ 90,600: It should also be noted that integral containers lose their CFC gas whereas a central plant is virtually gas tight.
An operating cost advantage of say $ 2.000 per day has a net present value of about $ 2.2 million on the basis that the ship has refrigerated cargo on board for 160 days per year.
When the NPV of the operating cost benefit is taken into consideration and the cost of the containers is included in the capital cost then the RPCC becomes very competitive.
BRS Hamburg
