EchoBolt Advances Wind Turbine Bolt Maintenance

Pete Andrews from EchoBolt discusses their advanced ultrasonic
technology for inspecting and maintaining wind turbine bolts, which
can reduce maintenance costs by up to 90%. He emphasizes the
importance of proper bolt tensioning during installation and
highlights recent improvements in their automated inspection
processes. Sign up now for Uptime Tech News, our weekly email
update on all things wind technology. This episode is sponsored
by Weather Guard Lightning Tech. Learn more about Weather
Guard's StrikeTape Wind Turbine LPS retrofit. Follow the
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Weather Guard on the web. And subscribe to Rosemary Barnes'
YouTube channel here. Have a question we can answer on the
show? Email us! Allen Hall: With wind turbines growing larger
and critical bolted connections under strain, the wind industry
needs smarter inspection methods to prevent costly failures. This
week we speak with Pete Andrews, managing director at EchoBolt.
EchoBolt has developed ultrasonic technology that makes bolt
inspections faster, more reliable, and saves wind farm operators up
to 90% on maintenance costs while preventing catastrophic failures.
Stay tuned. Welcome to Uptime Spotlight, shining Light on Wind.
Energy's brightest innovators. This is the Progress Powering
tomorrow. Pete, welcome back to the show. Pete Andrews: Hi, Allen.
Hi Joel. Good to be back. I was trying to work out when I was last
on here, but it was it two years ago. It's been a while. Anyway,
we've had a lot change at alt yeah, it's good to catch up with you
guys again. Allen Hall: It's been too long and so we're glad to
have you back because I know there's been a lot of improvements and
EchoBolt has been really busy checking bolts all over the place and
we've, Joel and I have been traveling around quite a bit and we've
noticed problems with. Bolts in the United States and we think
where's Pete? Where's Ebol? We could really use you in the United
States to help us on some of these bolted connections because it
does seem like there's a lot of issues from tower bolts to blade
bolts to bolts in general, there are a number of problems that
exist. And I wanna start off there, Pete, because I think you're
the knowledge base for bolts. Are bolts being tightened correctly
based upon all the measurements that you have done? Pete Andrews:
Say, it's a very mixed picture. I think you're right to point out,
it's every wind operator will have issues in their fleets with the
bolt of connections, but it's almost always. Blade studs that
caused the most headache. You do see things on towers. You do see a
kind of occasional issues elsewhere, maybe with foundations. I'd
say it's probably, I. In our experience, once, once sites are in
operation, there's not too much that happens that influences the
integrity. An awful lot happens at the point of installation, and
it's what we always try and say to customers if it. If you confirm
that the bolts are tightened to the load, you expect at the point
of installation, you've set yourself up for a fantastic operational
li life. But if it's wrong at the start, you've got embedded
integrity issues that are really hard to manage going forward. So
yeah it's a mixed picture, but what I'd always say is focus on the
QA at the point of installation and things should go easy from
there on in. Allen Hall: It does seem like blade bolts are becoming
more of an issue. As you mentioned, the blade insert question of
are we over tightening fasteners that go into the blades and
pulling out these inserts and causing some of the problems
downstream root cracking, instruments becoming loose, blades
becoming loose and wobbling on the pitch bearings. It does seem
like we don't have a really good way of consistently tightening or
tensioning. Those fasteners are bolts that are in composite
structure just a lot more sensitive to or the composites more
sensitive to the tensioning tightening that happens? I Pete
Andrews: think without doubt it's a harder joint to design and I
think probably all of the major turbine OEMs. It's the area, I
guess probably with the most dynamic loading or the most variable
dynamic loading and probably the hardest to anticipate the
performance of the joint. I guess we see a couple of things. We see
a. Occasionally you do get overt tightening, particularly on
torqued joints. Most blade studs tend to be tensioned, where you
stretch the bolt rather than turn the nut or the bolthead. But
where it's torked, you have a very wide degree of variability and
there can be, there can be issues with going back and retalking and
trying to measure an angle of turn and over overstretching the bolt
and failing them. So we've seen that. I think on the tensioned
joints, typically you get very good variability and the bolts tend
to be within a narrow band, but probably not enough is being done
to ensure that you've got as much preload safely within the bolt as
you can. And I think. The one meaningful action operators can take
without having to redesign the joint or try and redesign the
fastener, is just to measure the preload and see how much
operational headroom you've got and maybe look at increasing it
slightly. That's probably the one area. If you're suffering a lot
of TED failures, you can address quickly and cheaply without
getting into. Design fundamentals. Joel Saxum: Pete this week we
were at the Blades USA conference here in Texas and we had many
side, everybody's talking blades, right? So what blade issue do you
have? What blade issue do you have? And one of them that Allen and
I had a couple conversations on with operators, there was, oh, we
have the root bushing pullout issue. And some people were very
familiar with the issue and, but some people just weren't. They
were like, what do you mean by that? I was like, these things are
actually loosening in the, breaking bonds and pulling through and
all kinds of stuff. So in a blade root, you have upwards of a
hundred studs or a, or a hundred of those blade bushings. How many
of them have to start to become loose before it starts to be like a
cascading effect? For that blade, Pete Andrews: the failing of the
fixing within the composite structure is not really something we've
encountered or looked into a lot. I think typically most
manufacturers would place a limit on how many alts failed be before
you need to stop the turbine. Some of them have overall limits
about the number in the joint and some have adjacent limits. I
think it's pretty normal for people to run with one or two failures
and the structured still be still be safe to operate. But I think
where you start getting consecutive failures, you have to look
quite hard about. The decision to continue to operate the unit, but
particularly since the failures often in segments. So there is
typically leading and trailing edge segments where you'll see
higher risk of failure. So as soon as you've got a couple of bolts
in that area that aren't doing what they want or what they're
supposed to be, then yeah, I think it's a much harder decision to
carry on. Carry on operating without replacing those fasteners.
Allen Hall: Are there OEMs that are asking for those blade bolts to
be torque still or has everybody moved on to tensioning? I Pete
Andrews: think every modern turbine we work on is tensioned. Some
of the, we get quite involved in life extension projects where
turbines have got to sort 20, 25 year operating life. People are
trying to make an assessment of, is it safe to continue? Do we need
to do wholesale replacement of components, et cetera. And so a lot
of the older fleet or some of the older fleet would have talked
talk blade studs, but often, we can go in and if we can prove that
the bolts are operating in the preload envelope. The ideal preload
envelope, let's say. We can also look for defects, so we can look
if the bots have got cracks in them and help the people make that
call to just continue to operate safely with a monitoring regime in
place rather than perhaps following a recommendation. From an OEM,
which might involve wholesale replacement. Allen Hall: I think
that's fascinating, but I asked that question because there's a lot
of repowering happening in the United States, and it did seem like
turbines that are 10 plus years old. There was a lot of torquing of
blade bolts, and now that we're going to repower, one of the
questions is, do I need to go back and look at that blade root area
and do I need to address it because I overt, tightened, and or
retort over the years and damaged that root section. Is that
something that EchoBolt and its technology can actually check?
Because I think that's one of the variables that we don't know
right now is this bolted connection okay. To live another 10 or 15
years. Is that something that the technology at EchoBolt can
derive? We can Pete Andrews: definitely to derive the bulk loads so
we can have a look if. If the bolt is over or under tightened, what
we don't do is the structural non-destructive testing. So we
couldn't look at the blade root bolt fixing structure and make any
comments about the integrity of that. But we can look with you or
with operators. What's the tension or tithing process they've
followed? Does it generate the preloads that you would expect? Is
there a risk of overti or in the tighten box? So that's really our
specialism. Joel Saxum: What you guys do is very valuable at
different life's stages of a turbine, right? 'cause what earlier we
talked about hey, right at commissioning you should be doing, you
should be checking all these bolt connections or tension
connections. Either way. And then we talked a little bit we jumped
forward, talked a little bit about lifetime extension during the
repower phase. But another critical phase of life, specifically in
the States that we deal with all the time is end of warranty.