Advantages of Mark VI and Mark V over Mark IV?


Thread Starter


We have a GE Frame 5 gas turbine with Mark IV control systems. We are due for control system upgrading. Can anyone tell me what are the advantages of Mark V and Mark VI over the Mark IV?
The Mark V Speedtronic is no longer being produced by GE and they have issued an 'end-of-life' letter stating when spare parts will no longer be available (no; I don't have a copy of the letter to send to anyone; you have to obtain a copy from GE).

The Mark VI is slowly being superseded by the Mark VIe, which is a newer 'enhanced' version of the Mark VI that uses many Mark VI components but can be provided in a smaller enclosure thanks to some new methods of linking the I/O terminal boards to the control processors, which are also much smaller.

For those owners/operators with Mark IV turbine control systems, GE is offering something they call "Mark IVe" and also call "Mark IV Migration" (isn't GE wonderfully consistent?!) depending on who you talk to. It turns out that the terminal boards in the Mark IV can be unplugged from their stationary bases, leaving the field wiring connected to the terminal boards. From what I can determine they unplug all the terminal boards, remove all the Mark IV hardware from the control panel enclosure, install Mark VIe turbine control hardware and new terminal board bases in the Mark IV control panel, connect them all together, and mount an HMI in the door in place of the CRT and membrane switches. The new terminal board bases are in the same locations as the previous terminal board bases and the terminal boards with the field wiring are plugged into the new bases. There is some method which connects the terminal board bases to the Mark VIe components (I imagine it must involve some internal cabling).

So, there is no need to disconnect all the field wiring from the Mark IV terminal boards, remove the Mark IV and install a new control panel, and then reconnect all the field wiring to the new control panel. I'm told the entire hardware change-out can be done in less than four days; loop-checking still has to be done and that takes some time. But, not having to replace the panel and disconnect and reconnect field wiring is a *huge* time-savings.

HMIs can be remotely mounted using Ethernet or fiber optic cabling. Since the control system is a Mark VIe, future expansion would also be much easier than with a Mark VI. I'm also told the HMIs supplied with Mark VIe systems have a much-improved interface between CIMPLICITY and the Mark VIe (but they still use CIMPLICITY; I guess one has to take the bad with the good). One can use OPC to control and gather data from from the Mark VIe (through the HMI).

So, I don't think you can buy a new Mark V panel (possibly a 'new old stock' one, to use an eBay term), but getting it programmed and installed and started-up would likely be difficult and time-consuming and expensive. Buying a Mark VI would entail having to remove the old Mark IV panel and install a new Mark VI panel, which would likely take at least two weeks just to do all the wiring and panel replacement, and then loop-checks could begin. The whole replacement would likely (usually) take three to four weeks.

Using one of these "Mark IVe" or "Mark IV Migration" (I imaging the entire name is really something like 'Mark IV to Mark VIe Migration' and it's just been shortened) systems would result in the least down time (maybe less than 10 days) and the newest control system hardware that GE has to offer in the Speedtronic line. Sometimes a short outage is not a real issue, but the disruption of a complete control panel replacement, including having to make arrangements to remove the old panel and install a new panel, and all the wiring work can be a real pain. Not to mention having field engineers and electricians on site and all the "fun" that can bring.

To try answer your specific question, the Mark IV had limited data-gathering capabilities. It was an excellent and robust turbine control system, not without its flaws (as every control system has!), but extremely well-suited to the application. But, troubleshooting and data-gathering was very limited. It forced one to learn turbine operation and the really good troubleshooters and technicians learned how to use the Auxiliary Display to great advantage. However, the ability to gather data in electronic or paper form was very limited.

The Mark V addressed some of those issues with the software "tools" available on the <I> and GE Mark V HMI with much-improved data-gathering and troubleshooting capabilities. The Mark V turbine control hardware was not as robust as the Mark IV and configuring and understanding the Diagnostic Alarms was also very cumbersome. And, when HMIs were used, the difficulty factor in changing configurations greatly increased.

The Mark VI saw a return to more typical turbine control hardware (barrier-style terminal boards) but at a cost in terms of space--the panels were huge compared to earlier Speedtronic panels. The software tool used to configure the Mark VI, Toolbox, was a great improvement over editing numerous ASCII text files as was necessary with the Mark V, but the CIMPLICITY-based HMIs still present a challenge and many problems for lots of sites and applications. Toolbox has excellent trending capability (high- and low-speed) and some other really nifty and useful features (Watch Windows and graphical display capabilities itself!).

The software used for Mark VIe is an improvement (of sorts) over Mark VI. Instead of a single file used as was used for configuring the Mark VI itself, there are scores of files for the Mark VIe, but, thankfully ToolboxST keeps track of all of them in the one application. Again, the Mark VIe has very good trending and diagnostic capability, and very robust hardware.

Good luck in your upgrade!

We have 2 Frame 5 gas turbines in service since 1985 that we upgraded from MKIV to MKVI approximately 3 years ago. We did this for two main reasons: spare part availability and lack of experienced personnel comfortable with MKIV programming. We were also building a new plant that was going to use MKVI controls and felt this would minimize spare parts. I would think if you had ample spare parts and people comfortable with MKIV programming and diagnosis then there would be no reason to change since the MKIV has been a reliable system for the most part.

That said, if you need to upgrade I would suggest upgrading to a MKVI rather than a MKV since MKV parts are getting hard to come by and MKV HMI systems are also getting hard to support. I did talk to a GE TA recently who told me that a GE now has a MKIVE available; it is basically a MKVIE system using the old MKIV terminal boards. I am unsure how much this would really save over just installing a full MKVI or MKVIE system.

Lastly, if you do choose to upgrade I would urge you to talk to others as you are now doing and get their feedback. We hired an outside consulting firm to assist us with the upgrade which proved to be invaluable. Unfortunately, the GE TA we had for commissioning was not as knowledgeable as he should have been. Thankfully the consultants we had knew more than he did and were able to assist. As well GE did not adhere to our specs for the project, for instance lack of spare I/O, etc. that took 2 years to resolve. Like anything else I would urge you to educate yourself as much as possible before the process. Feel free to contact me if you would like any further information. I am certain Mr. CSA will have a wealth of information to give as well, and as always I look forward to his comments.

mthines at tid. org
Our company has two Frame 5s that have the Woodward Micronet control system on them. I believe that these were bought during the transition of GE buying Woodward back around 1999 or 2000.
This is a very commonly repeated "falsehood". GE did NOT purchase Woodward Governor Co. They purchased the retrofit services division of the Woodward Governor Co., which is the division which engineered and packaged prime mover controls primarily for power generation applications (turbines of all types).

Woodward Governor Co. still produces all of their turbine control products but they no longer engineer and package them in control systems and perform the installation and maintenance of those systems. They do have a network of control system integrators and vendor representatives (Recognized Turbine Retrofitters) that can offer packaged control systems and service on Woodward products, but the corporation no longer provides complete systems and engineering as they did in the past.
I want to know difference between mark vie hardware panel and mark vi panel because we want to evaluate is it better to do FAT for this mark vie panel
Dear PC,
the MKVIE has many differences from the MKVI, the biggest difference is that the MKVIE is Ethernet based so is easier to implement as a truly distributed control system. The controllers are smaller than the original MKVI and instead of using a 37 pin cable to connect the controller to its respective terminal board, all terminal boards and controllers have an IP address, so can be placed anywhere within reach of an ethernet cable or fiber connection.

The MKVIE also uses a newer and different version of Toolbox. For a typical turbine installation the MKVI is still great since all controls are usually very close to the turbine. MKVIE was primarily developed to be sold as a DCS. That said buying the newest equipement sometimes has advantages and disadvantages. Life cycle costs, equipment support, parts and training are just a few of the things to be considered. I hope this helps answer a few of your questions.
Hi sir,

If you don't mind (I hope you don't)... would you share with us on:

1) Reliability of Mark VIe based on your experience.

2) Total cost for Mark VIe per panel - rough ballpark figure will do - just for our budgeting purposes.

Hi James, why don't you call your local GE representative and ask him/her what the differences are between a new mark VIE and a new mark IV+ ?

The differences between your current mark IV system are at least 17 years of development.

Of course on this platform you can expect a coloured opinion.

lots of wisdom,
The MkIV+ is actually as stated earlier, a MkIV control panel that uses the existing I/O boards and is wired directly to the MkVIe controllers installed in the MkIV cabinet. All communication is upgraded to triple redundant ethernet. A Cimplicity HMI is the interface. The only components remaining from the MkIV are the field devices and terminal blocks.
I was being facetious.

A Mark IV+ is an Intel 80286-based Mark IV (the original Mark IVs had i8086-based processors).

What you are describing is the Mark IV-to-Mark VIe Migration, also known as the Mark IV Migration, or Mark IV M, or Mk4M.

It is sometimes mistakenly called the Mark IVe, but there is no such thing as a Mark IVe.

For the longest time at Loveland there where two signs at Woodward. One said GE at one entrance and the other said Woodward. Everyone thought GE bought out Woodward. GE was getting upset that Woodward was doing more and more retrofits. It boiled down to we are not going to buy the controls no more from Woodward. they agreed on Woodward selling the retrofit business for large Steam and Gas turbine's to GE. Woodward still produce's the Micronet TMR,505H, 5009 and other controls to GE. Since GE is an OEM they can buy directly from Woodward and the distributors usually do not get involved with these more expensive controls.

I'm more than a little confused by your posting.

GE didn't do anything more than any other business flush with cash would do when a competitor is being, well ... competitive. If you can't beat them, buy them. So, that's what GE did; they bought the retrofit services (and engineering) division of Woodward and for a few years they were co-located with Woodward in Loveland.

I would have to believe that the acquisition hasn't quite turned out as well as GE had hoped. A lot of fine, talented people decided they didn't like the "organization" that GE was bringing to their well-established business, and several companies saw an opportunity and opened retrofit engineering divisions in the Loveland area and lured some good people away from GE.

I would also have to suspect that the acquisition has had an affect on GE's turbine retrofit business, a positive one, but mostly because of the contract they negotiated with Woodward regarding the sale of programmable control systems which could be applied to GE-design turbines which has basically locked out a significant portion of Woodward control systems from being sold and applied to GE-design turbines. (It's rumored that contract has a short term left.)

Yes, GE will buy and apply some Woodward controls if absolutely required by a Customer to get a sale. But, GE would rather sell Speedtronic equipment. Much rather.

There are still Woodward RTRs (Recognized Turbine Retrofitters) who are "flying under the radar" on and doing some controls retrofits on GE-design units, and it's rumored Woodward is or has tried to package some Atlas-based systems which could be applied to GE-design gas turbines, but that effort seems to be stalled or abandoned or not well advertised or, it's difficult to say.

GE has recently moved their Control Solutions business to Longmont, CO, relinquishing the entire Loveland facility to Woodward.

Woodward makes a fine control system. I just personally have a few problems with it, and I also have a few (well, more than few, actually) problems with the Speedtronic control systems as well. The documentation for neither control system is very good. The programming application for both have pluses and minuses. One control system is basically extremely simple (bordering on too simple) and the other is extremely complicated (bordering on over-complicated). One requires very limited spare parts, while the other requires lots of spare parts--and both are proprietary.

But, I'm curious when you say "..we are not going to buy the controls no more from Woodward...." Who is "we"? And why aren't you buying controls from Woodward?

I'm sorry; I'm just really confused by (at least the wording and the order of statements) of your posting. GE was co-located with Woodward for a time in Loveland after the acquisition. Woodward does still produce a number of control systems for large prime movers and generator drive applications.

I'm sorry; I don't mean to be so dense. But, I'm not getting a point from this.