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@cybergibbons | |||||
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So I think at best... we have 750 * 120k = 90 Mega Bananas.
Enough for everyone in the UK and me.
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Cybergibbons! (Project Zero Hounslow)
@cybergibbons
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4. sij |
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So what is it?
It's power.
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Cybergibbons! (Project Zero Hounslow)
@cybergibbons
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4. sij |
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Even the biggest container ships - for example, the Emma Maersk with around 11k fully laden TEUs - only have 1k reefer sockets onboard.
Assume those are all filled with forty footers.
We are down to around 1k * 120k = 120 MegaBananas.
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Cybergibbons! (Project Zero Hounslow)
@cybergibbons
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4. sij |
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Wow, big difference!
But, it gets worse.
Those reefer positions all need power.
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Cybergibbons! (Project Zero Hounslow)
@cybergibbons
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4. sij |
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We used to factor around 4kW for a reefer... so that would be around 4MW total. Easy!
Problem is, bananas are not average.
Most frozen cargo is taken onboard frozen. It doesn't take much power to keep it frozen at -21degC
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Cybergibbons! (Project Zero Hounslow)
@cybergibbons
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4. sij |
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Bananas are different though - they are often packed warm, and brought directly to the ship.
They are also kept at +14degC.
This means the refrigeration needs to work harder.
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Cybergibbons! (Project Zero Hounslow)
@cybergibbons
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4. sij |
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We are now looking at as much as 20kW to cool that container when it comes onboard, and 8kW to maintain the temperature.
We've jumped to 8MW at least!
That's changed what you are doing in the engine room.
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Cybergibbons! (Project Zero Hounslow)
@cybergibbons
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4. sij |
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Each of the 5 generators on the Emma Maersk is around 4MW.
You are now running 3 generators just to keep the ship running in port!
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Cybergibbons! (Project Zero Hounslow)
@cybergibbons
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4. sij |
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Worse still, the shaft generator (the thing that recovers power from the main engine) is only 8.5MW.
You are now having to run extra generators. Not economical. But doable.
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Cybergibbons! (Project Zero Hounslow)
@cybergibbons
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4. sij |
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So where does all that heat go from the refrigerated containers?
The air.
That's fine above the hatches. But what about below the hatches?
Well, you need fans. And a lot of them.
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Cybergibbons! (Project Zero Hounslow)
@cybergibbons
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4. sij |
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No container ship I worked on had enough below hatch ventilation to handle 100% bananas. 100 containers dumping 8kW of power under a hatch is a lot.
Total guess, but I don't think you'd manage more than 75% of reefer being at full load.
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Cybergibbons! (Project Zero Hounslow)
@cybergibbons
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4. sij |
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How do shipping companies handle this? Well, there are actually special banana ships - they are open hatch and can easily handle the load.
Anyway, hope that was fun :)
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Cybergibbons! (Project Zero Hounslow)
@cybergibbons
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4. sij |
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This is what happens when you just multiply containers by how much you think is in them.
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Cybergibbons! (Project Zero Hounslow)
@cybergibbons
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5. sij |
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For those of you interested in what the engine room of a container ship looks like, I posted some pictures last year:
twitter.com/cybergibbons/s…
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Ken Munro
@TheKenMunroShow
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4. sij |
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Is that 90MB??
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Dave
@Dicty_Dave
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4. sij |
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But is 1 mega banana equal to a 1000 kilo bananas or 1024 kilo bananas here!?!
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Owe Jessen
@ojessen
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5. sij |
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Does this include the requirement to ventilate the boxes as the banana ripen on the transport?
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Cybergibbons! (Project Zero Hounslow)
@cybergibbons
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5. sij |
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Yep, reefers have vents and use the normal fans.
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nifty1a
@nifty1a
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5. sij |
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100Mega bananas is roughly the fatal dose of radiation. pic.twitter.com/bkEK5qW0m0
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Simon Farnsworth
@TrueFarnz
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4. sij |
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I now have the strange mental image of a man eating a single banana that's one million times the size of a normal banana...
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