The document discusses exploring the use of Pykrete, a mixture of water and wood pulp, for shipping containers to transport frozen goods. Pykrete was originally proposed during WWII to build large icebreaker ships but was never fully realized. The project aims to test Pykrete's properties through experiments and assess its suitability as an environmentally friendly alternative to traditional returnable containers. Initial tests found Pykrete has higher strength than ice while being cheaper and more thermally resistant than other materials. Further experiments are planned to characterize Pykrete recipes and design demonstration containers for user feedback.

1. Richard Farr
Nabil Gindy, Janet Folkes
Environmentally
Benign Shipping
Containers for Frozen
Goods – On Demand

2. Contents
Project aims
Historical context
Material properties
Market review
Experimental programme
Progress to-date

3. Project Aims
Assess the suitability of Pykrete for the construction of
environmentally benign shipping / storage containers for
frozen goods, with the aim of demonstrating:
Cost savings
Improved responsiveness
Better thermal protection
Greater eco-efficiency
(Pykrete is 86% water
ice, 14% wood pulp...
or similar.)

4. Historical Context
In the 1930s, Herman Mark and
Walter Holenstein, of the Polytechnic
Institute of Brooklyn, reported how
ice could be made much stronger if
the water was mixed with fibres.
During the Second World War,
Geoffrey Pyke had the idea that ships
could be made from this material.
A ‘bergship’ could not be destroyed
by the weapons of the day, and
might allow air cover to be extended
throughout the North Atlantic. Geoffrey Pyke
(1893 – 1948)

5. Historical Context
Project Habbakuk was to produce an enormous aircraft carrier,
with a hull made entirely from a frozen mixture of water and
wood pulp. The material became known as Pykrete, named
after its most enthusiastic advocate.
A 60-foot, 1000-ton Pykrete
prototype was constructed,
and floated successfully
on Patricia Lake in Canada.
Other tests revealed that
Pykrete was surprisingly
resilient. Gunfire and
explosives produced only
superficial damage.

6. Key points
Habbakuk would have had a hull at least 9m thick
The design called for an on-board refrigeration plant.

7. Material Properties
Impressive tensile strength
Cheap and simple – effectively free (in a cold environment)
Environmentally benign at end-of-life
Surprising thermal properties
Property Ice Concrete Pykrete
Approximate
strength,
kPa crushing test
3,450 17,250 7,600
Approximate strengt
h, kPa tensile test 1,100 1,725 4,825
Density, kg/l 0.91 2.5 0.98

8. Tensile strength
Ice is unpredictable, and weak in tension…
as this sculptor demonstrates

9. The ‘Mountbatten test’
There is a story that Lord Mountbatten demonstrated the
resilience of Pykrete by firing a revolver at two samples; one
ice and the other Pykrete. The ice shattered; the Pykrete
didn’t.
The story goes on to say that one of the witnesses, Admiral
King, was wounded by a ricochet...
We didn’t have access to a revolver – but small experiments
with an air pistol were possible.

10. Pykrete
“Recykrete”Waterice
Testequipment
The ‘Mountbatten test’

11. The ‘Mountbatten test’
...not very scientific, but it shows that water ice is reinforced
by the presence of fibrous material.
Various materials were experimented upon, including small
wood chips (hamster bedding), shredded paper, shredded
cardboard, cotton wool...

12. Time to melt
Ambient temperature 26ºC

13. Frost disappears from the ice before the Pykrete.
Pykrete retains its shape quite well... but when prodded, it is
found to have no strength. It’s just wet cardboard.
Further tests with embedded sensors required.

14. Specimen re-frozen after it
had completely melted
A ‘self-healing’ material?
Weight has been reduced by
40%, due to loss of meltwater
The remaining material is
surprisingly strong
A simple test shows its impact
resistance...
Lightweight Pykrete?

15. Market review
Using fish as an example...
Total value of the market in the UK: £2,295m
Up 1/3 since 2003 (Fish prices up 22%)
A global market, with high demand and limited supply
Fish now coming to the UK from further away
UK fish consumption actually below European average;
huge potential elsewhere
Figures from Mintel, September 2008

16. Market review
Figures from Mintel, September 2008
Presentation 2003 2005 2007
Frozen 0.35 0.34 0.35
Chilled 0.35 0.36 0.36
Canned 0.3 0.3 0.29
UK retail sales 2003 2005 2007
Fish tonnes
x1000
290 299 316
Fish £m 1,444 1,552 1,810
Shellfish tonnes 40 41 47
Shellfish £m 296 318 397

17. Market review
A very large, growing market.
Also vaccines, some meat products,
maybe other commodities.
All require containers that must either
be disposed of, incinerated, or shipped
back to the point of origin and cleaned.
A Pykrete container could simply be allowed to
“disappear” after use (86% water) reducing trade waste
disposal costs.
Residue of wood (etc.) may have some value.

18. Market review
The state-of-the-art container
is a returnable injection-moulded
tray, filled with crushed ice.
How do you know how many fish
you’re going to catch (and how
many containers you’re going to
need)?
Do customers always return the
containers? On time?
A Pykrete container would allow much simpler logistics.

19. Progress to-date
Range of laboratory experiments devised.
Means of producing samples determined.
Range of alternative ‘recipes’ for Pykrete proposed.
Relevant legislation concerning pallets and containers
has been studied.
Existing patents have been studied, and ten areas of
novelty have been identified, relating to:
Alternative ‘recipes’ for a Pykrete-like substance.
Additional features a Pykrete container might have.
Production equipment to make containers at speed.
Follow-on proposal drafted (CIP Eco-Innovation
programme) – call deadline 10/09/2009

20. Programme of Work
Laboratory experiments to be conducted:
Compression testing
Tensile testing
Specific heat capacity
Low-temperature creep?
... for each ‘recipe’ of Pykrete
Also assess the acceptability and performance in-transit
of a ‘demonstrator’ Pykrete container

21. Final report and
recommendations
Seek new funding to
commercialise findings
Design ‘demonstrator’
Pkyrete container
Interviews or visits to
potential users
Report on requirements
and market potential
Redesign
Month 1 Month 2 Month 3 Month 4 Month 5 Month 6
Contact potential users
Report on properties
of Pykrete
Seek reactions to
the demonstrators
Activity
Production of
samples
Design of
experiments
Literature, legislative
and industry review
Generation of
alternative ‘recipes’
Destructive testing of samples
Production of
demonstrators
Programme of Work

22. Common mistakes
“Pykrete is made with water and sawdust” - wrong. Pykrete is
water and wood pulp, which means
Pykrete wouldn’t have melted in seawater - wrong. Pykrete
melts readily enough... the ship was to have been kept cold
with a massive on-board refrigeration plant.

23. Questions?
Thank you for your attention!