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10 November 2007

Some Clean Air Ideas for HK Email 1 Plan A

From: Robert HO
Sent: Friday, October 12, 2007 10:34 AM
Subject: Idea: Used, jet engines mounted on rooftops to blow away polluted
air from worst affected areas of HK


Office of the Chief Executive
Hong Kong Special Administrative Region
People's Republic of China

5/F, Central Government Offices, Main Wing,
Lower Albert Road,
Hong Kong
Telephone : (852) 2878 3300
Fax : (852) 2509 0577
E-mail :

Dear Mr Donald Tsang,

1. I have previously emailed you on 18 Jun 05 on my idea of Govt By
Referendum [attached].

2. Yesterday, I read an article [below] on Hongkong's bad air pollution.
I have an idea that has a 50-50 chance of working.

3. It is to mount used [therefore very cheap] jet engines on selected
rooftops in Hongkong's worst air polluted areas to create enough powerful
winds and enough airflow to literally blow away the bad, polluted air.

4. How powerful is a jet engine? I remember an incident in Singapore's
Changi Airport that gives an indication. A plane's engines were being
tested in 1 part of the airport, near a perimeter fence. When the engines
were switched on, the gusts blew through the fence and overturned a car
parked beyond the fence [quite far away]. Thus, jet engines do produce
huge and powerful airflows up to a kilometre upwind and downwind. So, if
you have a series of jet engines mounted on selected rooftops of your worst
polluted areas, you could conceivably produce enough wind gusts to
literally blow away stagnant or still air that traps pollution particles
near ground levels.

5. There are some technical considerations. Since the jet engines produce
such powerful gusts, they cannot be 'aimed' at nearby buildings or
structures such as water tanks, roof structures, telecommunication masts,
advertising signboards, etc, as these would be blown away or damaged. So
this means that the jet engines should probably be mounted on high
buildings well away from such structures.

6. However, having said that, the engines should not be mounted too high
up like on the highest hills because clearing the air near the hills will
do little good. I doubt that the engines alone can create the kinds of
prevailing winds that Nature alone can. It is a localised solution to
clear the air in the worst polluted parts of the city to benefit the most
people -- meaning the most crowded parts of the city. Thus, the jet
engines should be mounted high enough to be safe to people and structures
yet low enough to clear the air off the most crowded parts of Hongkong,
thus benefiting the most people.

7. Considering that each engine will create about a Force 10-20 [I don't
know how big is a Force 10-20, really, just estimating] within a kilometre
of its location, both upwind and downwind, you probably only need 2-4 such
engines for your busiest and longest streets or crowded areas. These Force
10-20 winds should clear the air very quickly upon being switched on, even
though their effects will be quite localised. Thus, since they will not be
switched on all the time, they will be quite cheap to operate.

8. Of course, it is no use blowing away the stagnant, polluted air of 1
area if the air that rushes in to replace it is also polluted. So this
means that you should point the engines in such a direction that cleaner
air, probably from the sea, would be drawn in to replace the polluted air.
This should be easy given that Hongkong is an island surrounded by sea.
There may also be parts of Hongkong with cleaner air, such as the
non-industrial suburbs, whose air can be drawn in to replace the more
polluted air over the worst industrial or vehicular-polluted areas.

9. This means that the engines may have to be mounted on turntables or
large, circular gears so that a small electric motor [must not produce
sparks and must be shielded to prevent igniting the jet fuel] can rotate
the jet engine mounted on it, in any direction of choice. The jet fuel
will be stored in a simple, safe, tank like in airports, and pumped into
the engine, exactly like on a plane.

10. Since there is no danger to lives even if the engine fails to work,
you can buy old, used jet engines very cheaply, almost at scrap metal
prices. You only need to maintain and service it at very long intervals
since it may not be used daily or even often, so such maintenance and
servicing costs will also be cheap. Using used engines and standard fuel
systems means everything will be cheap because there will be standard
manuals and procedures for everything. Even spare parts and supplies. If
this idea succeeds beyond our wildest dreams, then you can develop real
prototypes of turbofan engines, etc, as real wind-makers, instead of just
cheap, off-the-shelf, second-hand engines and supplies. But that is for
the future. For now, we need to prove the concept first.

11. Since air pollution is not just Hongkong's problem but also much of
China's, it would be better if the China Govt sends its scientists and
engineers to Hongkong to help in and monitor this Proof of Concept test.
Beijing may also want to accelerate this test so that it can implement this
in time for the Olympics next year. If this works, the Pearl River Delta
may also want to do this to ease air pollution for itself as well as

12. If this works, looking ahead, precincts and districts or sub-districts
may also want to install their own rooftop engines to clear the air in its
vicinity so in the longterm, you may have to devise rules and regulations
for the safe and effective operations of such systems. You may also want
to require industrial estates or big polluters like some factories to
install their own engine/s to blow away their created pollution. Thus, if
this works, there will be some legislation or rules-making to devise proper
systems and functionings but these administrative measures will then be a
happy work because the crux of the problem will have been solved.

13. Currently, there is no market for used jet engines so you can buy many
at practically scrap metal prices. However, once this Proof of Concept is
done, there will be insufficient used jet engines for all the polluted
cities of the world. Hongkong alone will probably need a few hundreds. So
the prices will rise. This means that it may even be profitable for some
airlines and leasors to scrap their planes earlier due to the higher prices
for the used jet engines. Scrapping the old planes earlier will make
flying safer for all. A happy side effect of the idea.

14. However, there may be a bad side effect. Sometimes, an idea to solve
a problem solves it so well, but partially, that longer term and 'perfect'
solutions are therefore not attempted. The article below seems to
criticise your Govt for lack of legislation on punishing bad air polluters,
etc, and maybe you may have to devise 'perfect' solutions and maybe
legislation to restrict bad polluters. In the meantime, this is a
pro-active solution that any Govt or Municipal Authority can quickly and
cheaply implement and, if successful, become so publicised as a 'success'
and an effective 'action of Govt' that any criticisms of inaction or for
other restrictions on bad polluters will therefore become muted. In short,
it takes the heat off any Govt, especially criticisms of non-action. That
must be useful.

15. This idea is so new that other than what I have thought out, nothing
is established. Looking forward into the future, someday, some scientists
and engineers may well devise more effective arrangements of the jet
engines to create vortexes or vortices that, like a whirlwind, suck up bad
air into the higher atmosphere thereby drawing in cleaner air to replace
it. For example, by placing jet engines in a circle, each pointing up at
an angle of say, 45-60 degrees to the horizontal and slightly angled
inwards to each other, and switching them all on, a vortex of air may be
created that may, like a whirlwind, suck air up into the high atmosphere to
draw cleaner air to replace it. Thus, the science of JetStreaming or
WindShaping is created and maybe refined in the future.

16. I generally simply type out my ideas, email them off and leave them at
that. However, if you do want to discuss these ideas with me, in the
possibility that I may have further ideas and inputs when pushed or
challenged further, as has happened, do feel free to contact me. In the
meantime, all the best to you and Hongkong.

Salutations from Singapore,
Robert HO
12 Oct 07 1034

Robert HO
28 Bukit Batok Street 52
#20-03 Guilin View
Singapore 659248
Tel: (65) 68989553
HP: (65) 90127417

URL for the article on Hongkong’s bad air :


Dear XXX,
Air Science Group
Environmental Protection Department

1. I have anticipated all your objections except for the 1 that the engine will produce more pollution than it blows away. Interesting. However, the reason why I did not think of that is, as usual, it won't happen, or rather, the pollution from the engine is negligible compared to the polluted air that it removes. Also, the jet engine is operated only intermittently, for short periods of at most, an hour at a time, so not much pollution created.

2. I append below all the points that you have mentioned and my thinking on them plus all the ones I had already considered:

standard test kits to test air pollution in test areas, by vans? air pollution map of city

close windows, warning systems to close all windows to prevent papers sucked out

noise of engines to be muted by silicone window ledges and other soundproofings

simple concept to blow away bad air to explain to people

number of minutes or hours of operation to depend on severity of bad air

angle of aim of engine air thrust to be slightly coordinated not to counter each other in multiple installations

meteorogical advice on prevailing winds to help determine best aim directions

permanent air test stations near engines to help determine best aim directions

maps of wind directions to be charted more in detail at each engine; may need permanent wind mapping and data collecting over engine areas/districts for best aim direction

service personnel from engineers to engine mechanics to fuel pump mechanics

cranes to lift engines into place; maybe also fuel tanks -- bottled gas type? run hose from multiple bottles for convenience? determine how many litres/min of burn for tank size or number of bottles

engines to operate during specific times to minimise inconvenience? which times are worst air quality? night time disallowed/unnecessary?

highest buildings or mid highest? highest may be too high to be effective

consider special platforms purpose built for maximum effectiveness?

aim thrust vertically up? or at an angle towards up? in between building 'canyons'?

check rooftop building loads permissible; also stresses from engine thrusts, negligible

geared turntable to be firmly fixed to prevent flying off; emergency switch offs systems

turntable to rotate 360 degrees but not more, to be clock and then anti, not >360 for fuel lines and wiring

consider soundproofing walls/slats to minimise engine noise; consider channelling noise skywards; engine to be semi-enclosed by sound absorbers

warning to helicopters about starting engines to prevent being blown away; use emergency frequency at short range radio or helicopter frequencies to warn?

if rooftops near, warn people on nearby rooftops to avoid being blown away; may need system of nearby rooftop coordination when about to start engine; all these to be publicised in all media for general public, especially those who may work or visit rooftops near engine rooftop

no putting up of any permanent or temporary structures in line of engine, even if other rooftops

safety and stability of engine, tanks and others during typhoons and even lightning strikes

possibility of theft, sabotage, etc, of engine and arrangements

lightning conductors to be higher, thicker, etc, than engine, tank, etc, more numerous

Beijing tall buildings characteristics; those near Olympic avenues; Olympic duration and weather, bad air days, wind directions, find areas of good air for sucking into Beijing

sizes of engines available; their thrusts and fuel and other requirements; do survey

options to buy used engines; book early for cheaper prices and availability

good and bad air detailed map of city

explain and compare why even biggest industrial fans will not work, only jet engines; fans will not move air at ground levels while jet engines can create Force 1-2 winds even at base of building from Force 10-20 at rooftop

interesting possibility of using rooftop engines for non air pollution uses such as to 'cool' the streets on hot, windless days by creating light winds at ground levels



much alert and warning systems could be improved with permanent installations of CCTV cameras to check for open windows, people or structures on nearby rooftops near engine rooftop, etc, coupled with PA system installed together with CCTV for verbal warnings over loudspeakers

3. I have an alternative, which I call Plan B, which I will continue to refine. In the meantime, could you go through the above points and see whether they change your thinking and calculations? The thrust of the engine should not exceed rooftop building loads or sideway stresses, but do do some calculations on this. Thanks.

New Points in blue:
4. I know that this idea is quite startling in its boldness so may I suggest that if your department cannot test it out, why not let some other city take the lead in testing it out? You have my absolute permission and blessings to forward this to any other city authority or department that may be able or willing to test the idea. So, if you have contacts to similar departments in other cities or countries, why not forward these to them for testing? You can ask them nicely to let your department personnel be Observers to the test and if works, then you can implement it. But maybe, you should first contact Beijing because time is running out there to clean the air before the Olympics in August 2008. If they won't do the test, then forward to any other city in the world.

5. I also know that almost all companies and government departments don't like suggestions from outside their group. A suggestion from an Outsider is almost an insult, like saying, "I thought this up so how come you didn't?" so why not employ me as your subordinate? In name only of course, since I am in Singapore and you are in Hongkong. You need not pay me or pay me a nominal salary of HK$1 a month, if legally necessary. If you call me for a meeting or discussion, you simply buy return business-class tickets Singapore-Hongkong-Singapore. Plus hotel accommodation and daily expenses. That's all. As your employee, legally [I believe], any ideas and contributions I make will be your department's property and there need be no worry about later credit-claiming or litigation over intellectual property. I have a Plan B alternative idea that I am refining.

6. While you and your colleagues mull over the jet engine idea, why not do an Air Pollution Map of Hongkong? This will be necessary for any counter air pollution measure you may take so may as well proceed with it. It will be needed for both Plan A or Plan B or whatever measure you may want to take so you may want to collect the data for the Map. In fact, you probably already have such a map? Or can quickly create a computerised map from your existing data?

7. Your Air Pollution Map would be somewhat like a weather map, marking out the areas of highest air pollution at different times of the day, focusing on the highest density people places. There is probably little need to map the lush, green countryside, etc. Your map will guide you to future measures to counter air pollution. For example, if Central is most polluted Mondays to Fridays from 10am to 8pm, peaking at 2pm, and the Pollution readings exceed health standards, then, naturally, that may be where you want to take ameliorative actions, at the most polluted time/s. My Plan A and Plan B are ameliorative actions in that they REDUCE pollution rather than PREVENT it. Prevention can be done by forcing polluting factories to shut down or relocate well away or by forcing vehicular traffic to have cleaner exhaust or to ban some or all vehicles from designated areas but these prevention measures carry an economic cost and sometimes a social and political price. So it may be sometimes better to Reduce air pollution after it has been created, for economic, social and political reasons, although every means should be used for best longterm effects.

8. I hope I have made it a little easier for you and for our future cooperation. Feel free to phone me or email me. If you just want a quick and casual chat, you can simply begin a new email to me at this email address and begin with, "Just a quick and casual chat; do not cc to everybody" and I will treat it as just that. There, that's it for today. Regards,

Robert HO
28 Bukit Batok Street 52
#20-03 Guilin View
Singapore 659248
Tel: (65) 68989553
HP: (65) 90127417