Work starts on 11km rainwater tunnel

Pule' Carmel

Sep 22nd 2012, 15:18

Please note that to accellerate the water quickly to its maximum velocity, the entry into the dorga should be vertically down and not sloped so that the water is accellerated byt the full force of gracity and then directed into the tunnel through a beautiful matematical curve, DEFINETILY NOT A CONSTANT SLOPE AS THAT PHOTOGRAPH INDICATES. Mathematical note. For a ball to fall from one point to another point below it and at some distance away from it, the path is not a constant slope, but a special curve with a vertical slope to start with and then curving into the final lower height. It is a wonderful equation hence curve to derive.

Pule' Carmel

Sep 22nd 2012, 18:36

PLease May I add that due to the effect which I described above, this year, the Santa Venera Tunnel waas flooded for the same purpose. The entry LIP of the drain tunnel into which two people were sucked and rescued is too short for the tunnel to work at maximum efficiency. In fact the wall that fell down was a mark of this as that wall should not have been a wall but part of the lip into the tunnel. once again if the Santa Venera tunnel is12 by 10 feet in area and the water level at the lip is to be say two feet then the length of the lip should be 120 divided by 2 hence about 60 feet.

Such short lips into which the water drops to proceed to other stations exist at Farruga Bridge near tat-twiebet where the wall creates a dam and the openinging into the main floodwater channel causes what it caused.

Another such situation occured at Marsa/Millenia/Cassar? Powerstation area where the wall beside the main water channel created a dam and the small holes that existes in 2003 had not enugh drop lip to drain that huge buffer dam. Thank God that on my advice the drop lip was increased by the fact that the wall beside the Old Arches supposrting the Historic drains ( now one arch, I remember two arches) have been unbuilt to increase the water drop lip. The same must be made at Farrugua Bridge Qormi and sant Venera Tunnel and the new tunnel, Increase the drop lip please as it is no good making a tunnel and not that lip that feeds it.

Incidentally may I inform the ai=uthorities to go and take those plackards/ notices off the gates at the entry of Santa venera drain tunnel and at its the exit situated at Qormi flood water, for t hese metal large area notices are restricting the effective area of the Santa venera Tunnel.

So Please increase the drop lips feeding the channelas and the tunnels and take off those notices on the gates at drain gallery at Santa venera. Only trying to help, please understand.

Pule' Carmel

Sep 23rd 2012, 01:41

As the water in this Wied Incita tunnel would not be so clean what I am going to say needs careful consideration, but if the water was reasonably clean would the following be possible?

The tunnel would be built normally, but instead of having a normal solid floor/ground, short lengths of separate reservoirs will be built under the floor all along the 11 kilometer, their dept depending on the elevation of the tunnel from the sea bed.

Now when water flows into the tunnel, it would start filling the first reservoir and when this is filled it will overflow to fill the second and thus this is repeated till all the reservoirs along the tunnel are filled up. Then and only after all the reservoirs are filled, the tunnel would behave as a normal tunnel. with all the water running thorugh to side reservoirs and eventually to sea. But with this , no gates will be required and over the years dredging of the reservoirs will be possible and so convenient

Obviously the tunnel would have a side walk for servicing and in fact it would be a plaeasnt walk to go through the tunnel enjoying the water in the reservoirs. I calculate that such multiple reservoirs under this "Tunnel reservoir" design could hold just over 1,000,000 cubic metre and what is more, the water will percolate and dissipate to the water table more efficiently unlike what Philip Grech estimated, " maybe the bottom third!" . this reservoir system would add much more area of percolation/ dissipation/exfiltration. Also with such a system, the tunnel could be closed for the control of insect control. It is such a pity that the dam drains mixes with the surface rainwater in Malta. Pity such a pity.

At Vittoriosa fejn " Sabu is-sinjur" when young I used to enter a shelter and walk deep and I estimate that I would walk uphill to under xaghra to Bormla and then down to the dockyard near the Bormla regatta club.

I tell you that the side of the central shelter corridor was full of separate sleeping quarters which were all full of crystal clear water. I even saw an electrical substation down there and even triggered a carbon dioxide tube which was the fire protection for the transformers. I walked all the way down to the place where a large explosion took place in the ammunition depot about 200 years ago I believe. not far away from the Bormla regatta club.

Pule' Carmel

Sep 22nd 2012, 14:27

They have such a machine and as it was being unloaded from the ship, there was a photograph of it and a comment about theis machine in the Times News.
The Santa Venera Tunnel was also dug with a swinging arm robot whose power thyristors were maintained by some one I do know.
The Fgura Marsa tunnel was dug the old fashioed way through explosive put around a centra hole. The first to blow was the central hole and then as the debris moved out the peripheral holes where exploded and the debris fell in the centre. It was wonderfull timing but the vibrations rendered all this out of fashion to using rotary cutters with special tungston carbite tips and another welded materal whose name fails me sut it sounds like stalectite! but that is near enough.

Philip Mizzi

Sep 22nd 2012, 19:55

Profs Pule I like reading your technical blogs and find them very interesting, but at times very technical.

I think that the name that failed your memory is ‘Stellite’. This very hard material is generally deposited by manual metal arc welding. It is used to harden cutting surfaces such as those used on rock cutting machines. This material is usually deposited by using ‘Stellite welding electrodes’.
Stellite welding deposits are very resistant to friction-wear, abrasion and erosion. These properties are also maintained at high temperatures during rock cutting and other operations. Stellite is also resistant to oxidation.

Stellite alloys are also used as a weld hard-facing material on valves, spindles, and other parts subjected to extreme wear.

Pule' Carmel

Sep 23rd 2012, 00:16

Thank you Mr Philip Mizzi Stellite was the word I failed to remember. Thanks again.
I write these technical notes for I feel that our autorities concerned should give them consideration, and if they feel that I am wrong I do not miind if they reject them.
Most of my ideas are ideas I experimented with, and the idea is usually correct, what I have to learn is to type a little slower and not to press the keys on the side of what I want to press and worse still is that I hate rereading what I write as I really have not time for all thism but I feel I am writing my biography on the Times of Malta. I do hope that what I wrote about the floodwater channels at Qormi/ Marsa will help the residents to live a better life.
Perhaps I should be paid as a consultant!!! and ot give it all away from free,! as a Maltese Patriot should I guess.

Trevor Lorenzo Mizzi

Sep 23rd 2012, 01:58

@ Kevin Muller,

Here is the T.O.M article from July 28th that Prof. Pule mentions regarding the tunnel boring machine that was unloaded from a ship to be used to dig a 5 km tunnel from Pembroke to Maghtab for running heavy duty electrical cable in. Same machine that has been used for tunneling on the continent by the way.
The Americans have massive versions of these machines that are used to tunnel extensive underground facilities for the military and for secret black project operation bases.


http://www.timesofmalta.com/articles/view/20120728/local/equipment-to-excavate-interconnector-tunnel-arrives-in-malta.430467

R. Agius

Sep 22nd 2012, 08:41

Good point but for Christ's sake "reversus moses"??!!??

john vernon

Sep 22nd 2012, 13:54

If this nationalist government is so wise why has it taken then over 20 yrs to make a decision to at last save the poor souls that have been flooded year after year?

G Tonna

Sep 22nd 2012, 18:09

Because it is wise. In life it is all about priorities. So much investment has gone to create the multi billion economic and social infrastructure so important in creating a decent and lucrative future for this island It is now time to go deeper and take Malta to an even higher level.
Nationalist Governments have shown a capability of doing this and proof of this is the endless list of big projects that have benefitted Malta's presentation and image. It is puerile to criticise this government on the level of investment. The extent is unprecedented in the history of these islands.

J. Debono

Sep 22nd 2012, 07:54

Can you please read the article again and then comment

1. It said in the article water will be directed towards reservoirs and the obviously the excess has to be dumped

2. The tunnel on its own will hold 700,000cubic meters of water.

Pule' Carmel

Sep 22nd 2012, 09:54

Mr J Debono. This is very interesting. If the tunnel has a continuous slope from high level at one end and sea level at the other, then it will not STORE an ounce of water as all the water will run down the slope till the tunnel is dry, and even the debris will be carried peovided that the surface of the tunnel is smooth.
A "tunnel" will only store water if it is made a U shape " Bhal zaqq il hmar" where the centre is below the level on either end and then it will store water. With such a system however once the tunnel is "full "the flow of water will slow down and what ismore the heavy debris and silt will fall to the bottom and the tunnel will close up. I hope we are not being taken for a ride to suggest a " storing tunnel. Aything that stores rainwater will have to cater for a high degree of silting and this has to be cleaned often. With a reservoir this is functional but with a tunnel, one has to keep on digging tunnels thruogh the silt. Not so practical in my opinion, but may be others have someting better that I do not know of.
This tunnel can only serve to TRANSLATE WATER TO RESERVUOURS OR TO THE SEA and once it does that it empties itself and will not store as if it does " store " it will also store the silt and the heavy debris,
Please think about it.

Charles Vella

Sep 21st 2012, 23:24

Are you serious R Balzan?! This project started 2.5 years ago!! Vera is Super One biss tara, ghax sentejn u nofs ilu fuq il PBS, Net u anke Favourite News kienu rraportaw li beda x-xoghol fuq dan il progett! Kieku l'elezzjoni ila gejja 25 sena ghax matul dawn il 25 sena, hlief progetti li bidlu lil Malta ma sarux!!

I pity you.

C Cassar

Sep 22nd 2012, 08:54

Why don't you make the effort and contact the works department to find out? They will provide you with a high level plan for the project. It just takes a little proactivity from a citizen.

Philip Mizzi

Sep 21st 2012, 20:48

I am not an expert in this field, but I think that Marco Cremona’s proposal makes lots of sense.

Such proposal will not hinder flood relief if operated properly and will have 2 more benefits.

1. Help to replenish the water table.
2. Act as a huge water reserve.

Regarding point number one, if the rock formation will not allow water in these tunnels to dissipate to the water table, a huge number of boreholes can be drilled along these tunnels (if headroom allows, but if not, borehole machines can be designed and built for the purpose) to assist in this process.

What Mr Cremona can perhaps kindly clarify is whether such contaminated water coming from dirty roads can be allowed to find its way to the water table without having negative consequences to the water reserve in the water table!

Marco Cremona

Sep 21st 2012, 21:24

Philip,

Thank you for your comment.

Urban stormwater - even if severely contaminated by sewage - contains (very) low levels of chloride (salt) and nitrate, the two biggest known pollutants in our groundwater today. So, in my opinion, we must make every effort to channel low-nitrate low-chloride water into our aquifers, also to counter the high-nitrate water being infltrated from farms, fertilizer-laden fields and leaking cesspits and sewers. Of course, also to counter the chlorides being introduced from over-pumping from registered and non-registered private boreholes.

And what better low-nitrate low-chloride source is there than rainwater?

Ok, stormwater may be contaminated with sewage (although one should address the source first).

But... unlike nitrate, bacteria is not soluble so there is a very high probability that it will be filtered by the rock before the water reaches the aquifer. Of more concern, in my opinion, are (soluble) hydrocarbons and soluble heavy metals which may not be filtered/adsorbed by the bedrock. However, for decades we have been indirectly and unintentionally injecting stormwater (containing hydrocarbons and heavy metals?) into the ground (in soakaways, valleys etc.) and to date official records report no incidence of hydrocarbons in the water being extracted from groundwater pumping sources for the potable water supply. So what's happening? We really don't know as nobody has carried out any research on the matter.

This country to start carrying out some proper scientific studies before pumping millions of euros into infrastructural projects that may yes, mitigate the flooding problem in some parts of the island but do nothing to stop the depletion of our (ground)water reserves.

Philip Grech

Sep 22nd 2012, 08:03

The tunnel is meant to be lined & waterproof so any exfiltration will be accidental.
Also the water quality, especially where the runoff collects sewage overflows, could be poor - no treatment provided.
Again, one cannot expect exfiltration from the total surface area - maybe the bottom third.

Pule' Carmel

Sep 22nd 2012, 13:00

If a constant sloped tunnel is gated at one end to store water, then one gate at the end would have so much pressure on it that it would have to be very heavily constructed and in Malta to maintain a leakless gate of that size, well I have my doubts.
All one needsto do is to watch the manholes lift at the end of a down hill because of the pressuse build up due to the HEAD that is formed in the drainpipes. Remember the Barrel experminet, he filled the wooden barrel and simply tapped a small pipe ( acting as the tunnel) and as he lifted the pipe mearly 33 feet the barel burst open with the pressure generated. As for the silting if the tunnel is made as " zaqq il hmar" to be able to store then we have to keep digging future tunnels through the silt and the debris that become stagnant and dormant at the bottom. All bufffer reservoirs at Qormi/Zebbus were siltes such that no buffer reservoirs existed any more. NOw at Qormi near Farruga bridge near Tat- twiebet there is an effective buffer reservoir and while the main channel is running easy, that area is flooded due to this buffer reservoir effect. Just go and see this all around Qormi on the side of the Main channel. The Main channel runns but the Qormi people are flood. NOw what we want is for our civil engineers to design buffer reservoirs with no buildings smack in the middel of them.

Daniel Vella

Sep 21st 2012, 20:01

One moment as I'm sure you'll get a reply soon.... Or not?

carmel callus

Sep 21st 2012, 19:31

What do you mean too little and to late? If we had not joined the EU as your PL and Muscat wanted us to do when they opposed EU membership, from where would we have got the €56 million which will be spent on this project? Kif m'intom kuntenti qatt.

Nick Borg

Sep 21st 2012, 19:50

So tell us Mr Brincat,what do you suggest we do? If we had listened to your dear leader we would have had no options that for sure, cos we would still be out of the EU,but now we progress as we have been doing the last 25years,and you can't stand it or admit it....

Take off those blinkers for once!

Mary Ann Borg

Sep 21st 2012, 20:21

Yes, we should wait for Joseph, he will solve it all like he will solve the W&E bills for us all. And remember, yesterday he added that not only he will lower the tariffs, but also without sacrificing anything else. Mhux clever il boy jew?

gil falzon

Sep 21st 2012, 21:47

True. It's also too late to find cures for cancer too because so many have already died. Let's just stop researching ey?!

Pathetic comment. Sarcasm is the only answer to this.

Joseph Arpa

Sep 21st 2012, 23:28

@ Nick Borg
So according to you Nick, if we didnt join the EU we would just be starring at eachother and we wouldn't be capable of dong any projects....yet in your own words we have been progressing for the last 25 years, way before we joined the EU.
Nick......GET A LIFE!!!

R Bartolo

Sep 21st 2012, 20:04

"...the drilling of the tunnel is expected to take two years."

I see, we must be skipping summer in 2013 and 2014.

Mario Farrugia

Sep 21st 2012, 20:38

Another moaner !

carmel callus

Sep 21st 2012, 19:32

Which is this "brilliant idea"? Bil-paroli tghid li trid.

Alfred Cassar

Sep 21st 2012, 19:39

D Borg, infact according to the same Marco Cremona (see above) this is what the project is doing. Kif ma tifilhux tfahhru progett tant tajjeb u utli.

Marco Cremona

Sep 21st 2012, 21:28

Alfred Cassar,

I never said that this tunnel project will be channeling stormwater into the ground to recharge the aquifer. Indeed, I believe that this is not in the plans.

I have just proposed that the tunnel be used as a soakaway (i.e. that it will have the capability to dissipate the runoff to the ground), and I hope it has been considered/will be considered.

Please note that I am in no way involved in this flood mitigation (tunnel) project.

Marco Cremona

Sep 21st 2012, 21:31

Carmel Callus,

I believe that D Borg is referring to the GEO-INF Research project described in this link
http://www.timesofmalta.com/articles/view/20120905/local/Why-every-rain-cloud-may-have-silver-lining.435655

Alfred Cassar

Sep 21st 2012, 19:36

yes this is interesting to know

JOE CUTAJAR

Sep 22nd 2012, 07:22

One can always revisit the land reclamation project!

Alfred Cassar

Sep 21st 2012, 19:36

Mr Magri, was it solved by the Mintoff government though I appreciate he tried. Was it even tackled by the Sant government, no. As you know the government does not have all the money in the world so we need to tackle one problem at a time according to budget. Unfortunately we are not Saudi

E Gatt

Sep 21st 2012, 19:46

Ehhh it’s actually been 14 not 24 years. Like most of us, irrespective of PN or MLP sympathies, we forget the two years of the MLP failed government of 1996-1998.

Also Mr Alfred Cassar is right – we are not Saudi Arabia.

carlos ellul

Sep 21st 2012, 22:20

The city gate bla gate and the teatru bla saqaf had to take first priority.

Michael Magri

Sep 22nd 2012, 18:46

@ E Gatt.. Check your arithmetic please. Its from 1987 to 2012 less 1 and 1/2 years..

@ A. Cassar.. Dr Sant only had about 18 months and a big `hofra`. On the other hand Dom Mintoff had found another financial, economical and social disaster. He even didn`t have enough money to pay the wages etc of the government employees..!!

J Martinelli

Sep 21st 2012, 18:39

What will, in your opinion, klint?

Alfred Cassar

Sep 21st 2012, 19:33

Can you please give us an alternative

joseph borg st john

Sep 22nd 2012, 09:43

Klint was lucky to give us those 4 small words never mind an alternative.

Alfred Cassar

Sep 21st 2012, 19:29

Sorry m borg but this is a very stupid comment. As if, if water is collected from Attard, Balzan and B'Kara, the effects will not be felt in Msida !

Kif ma tiflahx tiehu pjacir u tfahhar inizjattiva posittiva bhal din!

Trevor Lorenzo Mizzi

Sep 21st 2012, 21:49

They are more likely to tunnel into Punic or Roman tombs or into a yet undiscovered prehistoric underground temple like the Hypogeum at Paola plus countless old water storage cisterns and forgotten ancient tunnels or even old cemeteries like that was found when digging for dock number 4 and 5 in the early part of the 20th century. I even remember grave bones were still dug up by the back hoe in this area in 1963/64 when these docks were enlarged.

joseph borg st john

Sep 22nd 2012, 09:53

miskin M Borg (SLM) wears a very thick red glasses very short sighted but then you have to excuse him as they say Labour never changes .

R Bull

Sep 21st 2012, 19:23

Absolutely agree !

Alfred Cassar

Sep 21st 2012, 19:32

Mr Farrugia, I don't think water can be directed to a valley as the roads in Balzan and B'Kara which flood are infact a valley themselves, there is no lower level to direct the water in unfortunately.

carmel callus

Sep 21st 2012, 19:35

You could have attended the consultation meetings which the Ministry organised, where all the information was given.

Mr Mike Farrugia

Sep 21st 2012, 18:09

Wishful thinking. Unless enforced by law and punishable with a fine, it will never happen in Malta.
Perhaps a 3 month notice and all households would be checked, would not be a bad idea............but since it may cost a vote, no party will have the guts to do it!

A Trapani

Sep 21st 2012, 18:10

Nature's valleys were backed years ago. Are you blaming this on the PN too by any chance ?

Kevin Camilleri

Sep 21st 2012, 18:11

money is being wasted because ages ago, people build in valleys. Valleys were not build in the past twenty years but years ago!

Ivan Calleja

Sep 21st 2012, 18:18

Agree 100%!! In the meantime we continue to build in valleys like Balluta and Wied il-Ghasel, Mosta just to name a few!!

A Trapani

Sep 21st 2012, 18:13

Better late than never. Why do we have to find something negative in every positive news that exists ? Unbelievable !

Joe Muscat

Sep 21st 2012, 18:29

A. Trapani.....because it shouldn't take 25 years to sort it out....Because we shouldn't have to wait for the Pope to come to Malta to re-surface a major artery, because it shouldn't take 2 years to fix the Luqa Road near the Airport, because Shouldn't have to suffer when we are paying all the taxes under the sun, with new ones being introduced every day. The people are sick and tired...And have had enough!....You are one of those Maltese who lives in a perfect Malta....me too but only in my dreams... Reality is totally different...Whether you accept this fact is up to you....The facts are the facts

J Martinelli

Sep 21st 2012, 18:48

@Joe (not Joseph) Muscat

You are absolutely correct since this type of flooding only started since 1987. The previous 16 years and the 100 years before that, don't count!

@ A Trapani

This is Malta, you know. You should be quite familiar with the usual people crapping anything this government does, good or not so good. The easiest thing one can do is to criticize everything knowing full well that from where he sits he is safe but unable to deliver nonetheless.