Rotational direction of GE F9001e Turbine

  • Thread starter Theophilus tetteh Ahia
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Theophilus tetteh Ahia

I have been working on GE F9001e turbines for some years now and it baffles my mind why all the GE F9001e turbines installed on our site do run in anti-clockwise direction.

Even though the bucket and the nozzle profile suggest or determines the direction of rotation but in other jurisdiction the direction of rotation is in the clockwise direction.

is it as a result of the generator design or other philosophical reasoning?

I will be very much appreciative if reasons can be given.

Hoping to hear from all soon
Theophilus Tetteh Ahia
Theophilus Tetteh Ahia,

Things that make one go, "Hmmmmmm."

Designers have to make a choice: clockwise or anti-clockwise.

There's a story that says the designers wanted to make the parts not interchangeable with other turbines. There's another story that says that many steam turbines rotate in the clockwise direction, and the designers wanted to distinguish gas turbines from steam turbines. I understand there's a new book out about gas turbine design (primarily from the perspective of a European manufacturer) that has some interesting details. (Too bad it costs nearly USD70.00.")

In any case, a decision was made and the rest, as they say, is history. I, too, frequently question some aspects of design--and in some cases one can find some "logic" or "reasoning" (however questionable) that helps to understand such design decisions. Quite often, it's just as simple as a personal preference on the part of a designer or group of designers. Might even have been the result of a coin toss, or best of three coin toss.

Generators don't really care what direction the rotor is rotated--except for bearings and oil flow, that is. Magnetism is magnetism--whether it be clockwise or anti-clockwise. (Of course, phase hook-up is important!)

A very important lesson I learned about engineering (in a very painful manner, I might add--so I've never forgotten it): Engineering is a series of compromises. Think about that. As products are being designed (software as well as hardware) some decisions have to be made about future direction as well as current capabilities, and there are ALWAYS the economic decisions to be considered (too many engineers fail to recognize the economic aspects of products and designs). Some of the decisions may prove to be faulty, in hindsight, while others may prove very prescient. Others will involve great efforts to undo or redo because of faulty thinking or lack of planning or changes in consumer sentiment.

Engineering truly is a series of compromises. Who know what decisions had to be made back when the first GE-design heavy duty gas turbines were being designed. Did they have to use some existing parts and materials? Did they have carte blanche to design everything completely from scratch?

Wish I had the definitive answer, but, obviously, I don't. As an operator or technician should you be concerned to the point of baffling your mind for years?

In the grand scheme of things, the same efficiency and power generator occurs regardless of the direction of rotation. Regardless of the hemisphere (which I've actually heard given as a reason for choosing a direction of rotation). Regardless of the type of turbine. Or generator (as long as the oil flows into the bearings in the proper direction and the phases are appropriately connected).
Hi guyz,

I have seen the Gas turbines and steam turbines in the plant, normally the steam turbine rotation is CW when looked from the drive end. the reason i could figure out is: in case of a worst scenario, if there is a fatal accident or problem in the machine. in case the machine will roll out of the casing, it will go to the other side or outside the TG hall, rather than hitting the control room which is adjacent to the Turbine operating floor.


Thanks for the information.

And, congratulations--the designers really planned well for plant and personnel safety!

Did they think to put an automatic sling to catch the rotor before it falls to the ground, too? That would protect the rotor and anyone or any equipment which might be damaged if the rotor rolled off the turbine deck.

If they also had the forethought to purchase a spare turbine shell re-assembly could be very fast indeed and the plant could be back online in just a couple of days instead of a couple of years..

That is presuming they also used a breakaway coupling between the turbine- and generator rotors--which is common for turbine rotors that are prone to escaping from their shells. (The turbine governor must be really upset when the turbine rotor gets away from the shell.)

In any case, you are indeed fortunate to be working at such a well thought-out and constructed site that they chose a turbine with a rotational direction to spare the operators and the control room from bodily or death and damage when the turbine rotor escapes from the turbine shell. You should also be buying lottery tickets, or betting on horse races as you are certainly a lucky person.