Richard Neale of LTC Worldwide takes a look at the problems involved in delivering high quality linen on cruise ships and offers solutions
The problems of delivering high quality linen at sea are being made much more complex than they already are by the need to minimise operating costs and the increasingly critical demands of passengers for textiles in cabin restaurant and spa which are visually clean and stain-free, with no creases and no unpleasant odours.
Developments in laundry chemistry and machinery have helped considerably, but much more is needed, not least in manager and supervisor training and dissemination of the latest research results. There is even certification available for those who can now meet recognised disinfection standards, which is one sure way of reducing vulnerability of the ship's crew and passengers to stomach bugs and viruses such as Covid-ig. We look at what is now ready for adoption worldwide and where there are still gaps.
Cruise liner laundries have to cope with consistently high occupancy rates and a large number of guests, who to use their cabins much more intensively than say users of a 5-star hotel in a capital city. This gives a high demand for duvet covers, pillowcases, sheets and towels which have to look good, smell sweet and be crease-free, with frequent changes of linen being the norm. Shipboard laundries used to rely on large washer extractors to cope with the volume and many still do. However, the leading operators are tackling the challenge of running large continuous batch tunnel washers (CBTWs) at sea and reaping the benefits of greatly reduced costs for labour, energy, chemicals and water. The best are cutting more than 50% off the unit cost of washing, although they are still faced with the problem of the inertia, in heavy seas, of a large mass of water and textiles rotating with the washing action while being thrown around by the mechanical action of the ocean swell. In rough seas there is still the risk that the CBTW must be shut down until waters calm, which could require a significant buffer stock of clean textiles.
This problem is almost certainly soluble: the mass of the CBTW is no greater than that of other rotating machinery (such as the engine) while the force of the linen and water sloshing around in the machine should be no greater than that of the liquid surges in the fuel tanks.
The nub of the perceived problem probably lies in the risks at two critical points in the CBTW wash cycle. The first is at the point when the main tubular body of the machine has to rotate through 360°, in order to transfer the contents of each stage in the washer to transfer cleanly forward into the next compartment. Any interruption at these transfer points (for example surges in heavy seas) risks causing a textile jam-up in the tunnel washer, which is time consuming and dangerous to fix.
There have been several deaths on tunnel washer lines on land and special procedures are now necessary for unblocking. These are tedious enough on a firm laundry floor and much more difficult in an ocean storm.
The solution to this first problem probably lies in the design of the CBTW at the transfer points, which may need to be modified to ensure that it cannot block, whatever the forces the CBTW is subjected.
The second problem is closely allied to the first and concerns the transfer of the rinsed linen from the end of the washer tube (the final compartment) into the dewatering press. For the press to work properly, this transfer must result in the saturated linen in the press basket offering a reasonably flat and level surface, so that the descending ram of the press can get a firm, uniform squeezing action onto the cheese of textiles to be dewatered.
If the cheese happens to become tilted by the ocean swell (so that it is much thicker one side than the other), then the press can become mechanically distorted, requiring downtime and expensive repair. This could be a more difficult problem to overcome, but it is every bit as important as the first one. Once the design of the CBTW has been modified slightly to address these two problems, then there is a real prospect that the very significant operating cost benefits of the CBTW versus the washer extractor can be enjoyed by every cruise liner afloat.
A cruise liner has to cope with a mass of humanity living in close proximity and it is therefore more susceptible to infection outbreaks than a typical five star hotel. This requires special procedures in the laundry (and in many other places) and failure to instigate these protocols increases risk proportionately. Firstly, it is good practice to use disinfecting washes for all passenger and crew linen and garments. This is vital for hand towels, table napkins and pillowcases, which are likely to come into contact with human hands, mouths eyes and faces, but the consequences of an infection outbreak and the accompanying newspaper headlines are so serious that it makes sound sense to disinfect in every classification.
At one time, every disinfection cycle in a shipboard washer extractor relied on implied thermal disinfection, with the main wash held at a minimum temperature of 71C for a minimum of 3 minutes plus mixing time. Mixing time varied from less than one minute for a small washer up to over 4 minutes for the largest. Observers have reported that these processes were not used consistently, simply because the overall cycle time was so much greater than those which appeared (visually) to work all right at lower temperatures, the key difference being in the warm up time needed. With the advent of the latest chemical processes, which provide disinfection at lower temperatures (typically down to 40C), there is no excuse based on cycle time for not achieving disinfection on every item processed. There are now processes available, from every leading supplier, which not only give a 5 log10 reduction on most micro-organisms ( which is adequate for most national healthcare standards) but also deal effectively with Covid 19. Leading cruise liner fleets are adopting these long-sought solutions, but is by no means universal.
It is now possible to increase passenger confidence, very significantly, by instituting a simple onboard control system for the disinfection standard actually being achieved. The basic principles of this are set out in the European Norm 'EN14065:2016 Laundry processed textiles – Biocontamination control system' which was mentioned in LCN in May this year and reviewed in detail in the July-August issue 2020. This is a straightforward system readily applied to shipboard laundries and highly desirable for any high-quality liner.
For many years, cruise liners have relied heavily on sodium hypochlorite (‘chlorine bleach’) for removing the three main stain classifications vegetable dyes, food fats and mineral oils. This works very well for vegetable dyes from tea, coffee, red wine, beetroot, blackcurrant and so on and also contributes to disinfection at the correct level. However, relying on chlorine bleach for food fats and mineral oils is unwise, because heavy dosages are required to burn away the food fats or degrade the outer surface of the cotton. The result is much greater damage to the natural cotton, linen and wool fibres in shipboard textiles and very high replacement costs. These can no longer be afforded in the present financial climate and the time has come to institute modern stain removal systems. The latest laundry chemistry from leading suppliers worldwide utilises a much milder oxidation system for the vegetable dyes, coupled with tiny doses of targeted emulsifiers for fats and oils. There are even special processes for spa textiles, contaminated with difficult to-remove spa products, which have been associated with unexpected fires, especially immediately after laundering.
The effect of these improvements is to improve linen life from an estimated 60-100 wash-and-use cycles to 120-200 cycles. This translates into a halving of linen replacement costs, so it is well worth the management effort and the new chemistry is now almost certainly available at every port of call.
Traditionally, two or three factors have hindered the visual quality of bed linen and restaurant table textiles, resulting in limp fabrics with unsightly residual creasing. The first is failure to recognise the importance of removing as much moisture as possible after washing by mechanical action. This means fixing optimum spin times in washer extractors (so that another half minute does not increase the moisture removal). For the CBTW it requires maximising the time at full pressure in the mechanical de-watering press. A 40-bar press typically needs at least 30 seconds at full pressure. This should allow the textiles to go straight from the washer-extractor to the ironer and reduce the time spent in the dryer on the CBTW line down to less than two minutes (just enough to break up the 'cheese' of textiles).
The second problem has been the requirement imposed by the shipboard utilities design to operate the ironer at too low a steam pressure (with pressures as low as 5 bar on some vessels). A modern laundry ironer is designed to operate with 8 – 12 bar steam pressure, in order to get a smooth, crisp finish on sheets and pillowcases (which will delight the passenger, who will both see and feel the difference).
Leading machine designers believe that they are now very close to solving (or have already solved) the perceived problem of operating a CBTW in heavy seas. Adopting the modern machinery and chemistry now, that use the latest research, should enable a halving of both wash costs and textile replacement costs. With tight margins in an extremely competitive market, this needs direction at main board level for every fleet, to seize the opportunities and drive them home, firstly in laundry design and then at sea.