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    For a more detailed inspection the skipper managed to strand the dredge on a sand stripe in the middle of the Tagus during the low tide. This is the place where I tell you that one very good thing about this job is that you often find yourself in pretty cool scenarios - for example - I took this picture standing in the middle of the Tagus river, in the spot that in a couple of hours would be eight feet under water! Plus I got there in a cool tiny motor boat!... Anyhow, we (once again) inspected the closing gap for foreign objects - and (once again) none were found. Since the previously mounted temporary steel stripes could work as a jamming point they were removed - and still the barge wasn't closing. The cylinders were accessible now, so with an enormous effort and a lot of ingenuity and help from the sailors I managed to disengage the front pin and suspend the "malfunctioning" cylinder -  and of course now when the rod end got pressurized the rod went back all the way for another couple of inches. I was sure that all the doubts were cleared, and yet the owner still wasn't believing that the barge couldn't close for other than hydraulic circuit related reasons. He kept telling me that it was impossible and I kept telling him that it was impossible, with my "it" being the complete opposite of his "it". It was a classic standoff  - but I still had one last ace down my sleeve...

    By the "last resort ace" I mean "retreat and come back with reinforcements". I made a sad face, and admitted that I, naturally, could only draw my conclusions on the basis of my personal and very limited experience, and of course I could be mistaken. But what I could do was bring along a much more experienced and much better titled "second opinion", that would surely clear all the doubts.

    "Not to fear, me sea fellows - said I -  for the next time I am back, I shall bring along the engineer of engineers, the man of boundless erudition and colossal experience, the man who once stopped a train with a calculator and who shines his shoes with an angle grinder... He will come and he will heal the cursed vessel, and then she will close, my friends, CLOSE I tells you, and she will dredge like she never dredged before!!!"

    On the next day a colleague of mine came along and we took a nice boat ride to the barge, stranded in the middle of the Tagus. My colleague, unlike myself, carried along two "big guns" that never fail - an awe-inspiring engineer's title and  a respectable middle-aged appearance. When the man inspected the system and repeated the same opinion I'd been trying to sell for the previous three days, most of the crew got convinced it was true, and yet the owner was still somewhat unsure - "it must be the oil pressure or something..." - the man kept saying...

     At that point it was no longer a troubleshooting event, it was a "find a way to convince this fellow" affair. In the last attempt to prove our point  we came up with an ingenious plan - OK, say your hydraulics does have a malfunction or lacks pressure - but what if we bring along a completely new power-pack, capable of reaching much higher pressures, and connect it directly to the malfunctioning cylinder, thus eliminating completely the existing circuit? And then raise the pressure to a much higher level that the normal working one? The owner thought a little about it - and then gave it a go.

   We brought a new power-pack onboard, and connected it to the rod end of the "malfunctioning" cylinder, while the other end was intentionally left open to show that there was no but atmospheric pressure in the cap end (and also to check for any internal leakage). I turned the power-pack on - and the dredge was still not closing. I raised the pressure to 150 bar - nothing, 200 bar - nothing, 250 bar - still nothing, at this point I told the owner: "Look, you have a simple cylinder (no anti-drop valves inside) that has 250 bar at the rod end, and zero bar in the cap end, no internal leakage - since no oil was coming out of the open cap end connection, and we know for a fact that the rod can move for another good two inches - which means that at this point the cylinder is not closing because the structure is not letting him close. Why? Don't know really, but since no foreign objects jamming the hull were found, the only explanation I could find was that the complete hull structure was crooked in relation to the hinges' axis, and the closed bow was in fact the mechanical stop. The boxed construction of the hull made of reinforced steel was stiff enough not to bend even under the enormous force of the cylinder.  Then I added that that if he wanted to continue with the experience, it would have to be done at his own risk, since without having any hard data about the cylinder walls we could be already passing the safe pressure level - the owner reflected for a minute, and then said: "no need, take the hoses out, connect the system back the way it was - we'll have to continue working the way we were..." Aleluia! Finally our point was proved... Although I was kind of hoping the man would want to go to higher pressures - to see if we could "straighten the crooked dredge out"...

    Now what can be learned from here? Psychology, my friends, it's all about psychology - we troubleshoot machines, but we deal with people behind them - never forget about it! No matter what we do, there will always be those who judge a book by its cover and a technician by the amount of Grey hair, so instead of flipping on the "stress mode" we'd best learn how to live with and find our way around that!