22.12.2012 Views

Protection of Fuel Tanks Safety ahead! - GL Group

Protection of Fuel Tanks Safety ahead! - GL Group

Protection of Fuel Tanks Safety ahead! - GL Group

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Cool Transport<br />

The shipping <strong>of</strong> perishable goods in refrigerated containers is booming. Sophisticated<br />

refrigeration and ventilation systems inside the vessels help to reduce operating costs<br />

ASalmon from Alaska, lamb from New Zealand, bananas<br />

from Honduras: the food on dining tables in Germany<br />

and elsewhere has <strong>of</strong>ten travelled thousands <strong>of</strong><br />

nautical miles. According to statistics from Drewry Shipping<br />

Consultants, 57.1 million tons <strong>of</strong> refrigerated cargo<br />

were shipped across the seven seas in 2005 – more than<br />

twice much as 25 years ago.<br />

The bulk <strong>of</strong> perishable goods is now transported in refrigerated<br />

containers – which poses a big challenge for designers<br />

and shipbuilders alike: if the refrigeration units<br />

in the containers are to work efficiently, cool air must be<br />

pumped into, in particular, the ship’s hold and the warm<br />

air pumped out.<br />

Germanischer Lloyd’s new simulation system enables<br />

ship designers and shipyards to construct effective ventilation<br />

systems for any ship type. <strong>GL</strong> Vent simulates different<br />

operating, load distribution and temperature situations.<br />

The s<strong>of</strong>tware provides the necessary data for the installation<br />

<strong>of</strong> effective and economical ventilation systems and<br />

analyzes the weaknesses <strong>of</strong> fitted systems.<br />

Enormous Cost-Saving Potential<br />

Demand is growing. Although around half <strong>of</strong> all bananas<br />

are still being transported on reefer vessels, hardly any<br />

new vessels have been built for years, and the trend towards<br />

refrigerated containers is stronger than ever before.<br />

The annual transport capacities in this sector are now rising<br />

by 14% on average, which is even faster than the overall<br />

market for refrigerated cargo. Ten years ago, capacity was<br />

267,000 TEU; this figure has now reached 746,000 TEU.<br />

Currently there are 2200 vessels worldwide that transport<br />

CONTAINER. The<br />

refrigerating set needs a<br />

suffi cient ventilation.<br />

Source: Drewery Shipping Consultants<br />

refrigerated containers. The largest <strong>of</strong> these, the ‘Monte<br />

Cervantes’ owned by the shipping company Hamburg-Süd,<br />

has a total loading capacity <strong>of</strong> 5100 TEU, <strong>of</strong> which 2450<br />

TEU can be used for refrigerated containers.<br />

There are still two different container types in operation:<br />

integrated containers with an inbuilt refrigeration unit, and<br />

porthole containers without any additional refrigeration.<br />

However, most shipowners have gone over to using integrated<br />

containers. In 2002, the proportion <strong>of</strong> porthole types<br />

on the world market was less than five per cent.<br />

As for container loading capacities, the trend is towards<br />

a larger volume inside the container. Traditional 40-foot<br />

standard containers with a height <strong>of</strong> 8’ 6” are increasingly<br />

being replaced by high-cube containers (height: 9’ 6”).<br />

Nonetheless, 20-foot containers are still just as important<br />

as before. Heavy reefer cargo, such as meat and fish, would<br />

soon exceed the maximum weight <strong>of</strong> 30 tons if stuffed in<br />

larger containers.<br />

As the number, size and weight <strong>of</strong> refrigerated containers<br />

grow, they are increasingly being stowed in the ship’s<br />

hold rather than on deck. To make sure there is sufficient<br />

cooling, the ambient air temperature may not exceed 45 degrees<br />

centigrade. A 40-foot container requires 4,500 cubic<br />

metres <strong>of</strong> air per hour, and a 20-foot container needs 3,100<br />

cubic metres. This is because, depending on the goods and<br />

room climate, a stand-alone 40-foot container produces<br />

between 7 and 15 kW <strong>of</strong> heat. These values increase even<br />

more depending on how many boxes are in the hold.<br />

<strong>GL</strong> calculations prove the economic importance <strong>of</strong> sophisticated<br />

and optimized ventilation systems: if there are<br />

700 TEU in the ship’s hold and the ambient air temperature<br />

drops by one degree, the energy consumption <strong>of</strong> refrigerated<br />

containers with frozen cargo is reduced by 3.8 per cent<br />

and that <strong>of</strong> containers holding frozen fruit by 2.1 per cent.<br />

According to these calculations, the ship operators save approx.<br />

EUR 50,000 per year in the operation <strong>of</strong> their ventilation<br />

systems – and salmon, lamb and the rest are sure to<br />

reach their destinations in perfect condition. ■ JH<br />

For further Information: Hanspeter Raschle, Piping Systems/Tanker,<br />

Phone: +49 40-361 495 69, E-Mail: hanspeter.raschle@gl-group.com<br />

15<br />

10<br />

5<br />

0<br />

Bananas<br />

Meat<br />

Citrus fruit<br />

<strong>GL</strong> VENT | MARITIME SERVICES<br />

Development <strong>of</strong> refrigerated cargo transport<br />

millions <strong>of</strong> tons<br />

20<br />

Saisonal fruit<br />

Fish products<br />

Diary products<br />

nonstop 4/2006<br />

1981<br />

2005<br />

19

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!