Engineering and Technology Thread

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STEVE G
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Re: Engineering and Technology Thread

Post by STEVE G »

One thing that I did read somewhere, is that there are accumulators in the hydraulic systems that allow it to return to a safe position in the event of a major power failure or fault.
The airline I work for has a couple of 747 simulators, which are nothing to do with me but I've had a look at them and they use a series of large accumulators to allow for violent movement outside of what the hydraulic pump can manage.
As you pointed out above, the basic structure is very similar to a full motion aircraft simulator.
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Re: Engineering and Technology Thread

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STEVE G wrote: Wed Nov 29, 2023 4:35 pm
One thing that I did read somewhere, is that there are accumulators in the hydraulic systems that allow it to return to a safe position in the event of a major power failure or fault.
The airline I work for has a couple of 747 simulators, which are nothing to do with me but I've had a look at them and they use a series of large accumulators to allow for violent movement outside of what the hydraulic pump can manage.
As you pointed out above, the basic structure is very similar to a full motion aircraft simulator.
Yes, accumulators are used for several different reasons in hydraulic systems. In your case they do provide extra fluid when the demand of the system exceeds the capacity of the pumps. In other systems they act as pulsation dampeners to smooth out system pressures. There is some interesting info on old water type accumulators used historically in the UK on Wiki.

Several systems on offshore rigs use accumulators, mostly gas over oil types, and mostly as a dampener function.
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STEVE G
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Re: Engineering and Technology Thread

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^I never knew about this until you mentioned it but I've been having a read and apparently for over a hundred years there was mains hydraulic power available over 150 miles of pipes in London used for operating lifts, cranes etc.
https://www.subbrit.org.uk/features/hyd ... in-london/
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Re: Engineering and Technology Thread

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STEVE G wrote: Wed Nov 29, 2023 8:36 pm ^I never knew about this until you mentioned it but I've been having a read and apparently for over a hundred years there was mains hydraulic power available over 150 miles of pipes in London used for operating lifts, cranes etc.
https://www.subbrit.org.uk/features/hyd ... in-london/
For most people the mention of hydraulics brings to mind a JCB, or something similar, that uses lubricating types of oil under pressure.

Water has always been the first medium used in hydraulic systems, and in fact is still in use in a lot of instances. Sticking with offshore equipment, subsea hydraulic control systems use fresh water, as it does not polute the ocean in the event of a leak, or even venting as part of a specific function.

Some interesting facts here:

https://en.wikipedia.org/wiki/Hydraulic_accumulator
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Re: Engineering and Technology Thread

Post by Dannie Boy »

How clever are some people - love to see this in a working model.

https://youtu.be/NGF3jA8HYlw
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Re: Engineering and Technology Thread

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Re: Engineering and Technology Thread

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Impressive, when you consider trains in Thailand max out at about 80kph. :shock:
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Re: Engineering and Technology Thread

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Yes, very impressive, but I wonder about the reliability/cost of the tracks i.e. is all of the technology in the train, or does it require special tracks? If the tracks aren't special, and there's no contact with them, why use tracks at all?
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Re: Engineering and Technology Thread

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Big Boy wrote: Thu Jul 10, 2025 11:38 am Yes, very impressive, but I wonder about the reliability/cost of the tracks i.e. is all of the technology in the train, or does it require special tracks? If the tracks aren't special, and there's no contact with them, why use tracks at all?
The + and - magnetic connection has to come from somewhere to make it work. I think the cars are one and the track the other.
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Re: Engineering and Technology Thread

Post by Big Boy »

In my simple mind, it is like comparing wi-fi and hard wired. An aircraft would be wi-fi, go anywhere, etc. One of these babies needs a lot of cabling (tracks) and can only go where the cabling goes. Nice, but very limited use.

BTW, they are the ones who made the aircraft comparison.
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Re: Engineering and Technology Thread

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This would be no different than any other train in as much it could only go where the tracks are - the reference to planes was I’m sure only in relation to the speed equivalent - better have good brakes though!!


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Re: Engineering and Technology Thread

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Not sure about "limited use" trains have been in use for over a hundred years. I'd rather get to Bangkok on one of those babies in half an hour than the three hours it currently takes (four by road).

The Shinkansen in Japan gets from Tokyo to Osaka quicker than a flight, and the bullet trains in South Korea are even faster! These things are the future (well, maybe not in Thailand.)
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Re: Engineering and Technology Thread

Post by Dannie Boy »

Even with the introduction of the dual track lines, the trains running between HH and Bangkok remain the same slow rolling stock from yesteryear - even something nudging 120 kph would be a big improvement on what we currently have - this levitating train would be for a “next life” as far as Thailand is concerned.


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Re: Engineering and Technology Thread

Post by STEVE G »

And to think that the Mallard, a British steam locomotive managed to break 200kmh pulling a train in 1938!
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