welding tractor for bridge - 2 lines railway span

Post by Richard Smith
Hi all
Need advice "from zero upwards" about using welding tractors.
We have a bridge to make. Overbridge over a railway. Two lines.
Structurally it's typical steel bridge type - sides / "parapets" form
two main load-bearing beams, with connecting floor forming an
overall
"channel" structure. With the road traffic flowing "through" /
largely within the structure.
Lots of fillet welds - but some butt, for seaming plates together.
Wish is to use welding tractor to highly mechanise the weld. Avoid
stop/starts, promote extreme consistency of the weld runs, etc. All
things to send the fatigue endurance way up.
Don't know what questions to start to ask...
Where do I start?
What do we develop?
Then moving into production - what's the real deal?
Etc.
Rich Smith

https://www.lincolnelectric.com/en-us/equipment/robotic-automation/Pages/automated-solutions.aspx

I've watched their automatic equipment welding hull plating in a
shipyard.

Richard Smith

2018-08-31 02:55:41 UTC

Post by Jim Wilkins

https://www.lincolnelectric.com/en-us/equipment/robotic-automation/Pages/automated-solutions.aspx
I've watched their automatic equipment welding hull plating in a
shipyard.

Hi Jim

Thanks and did enjoy looking at the Lincoln stuff.

That page shows robotic equipment. We are way way down the scale.
Web-search shows things like the "Esab Miggytrac B501".
Explanation - would never be weaving. Set Amps and Volts and get your
fillet in a straight run. So never need the facilities of a good
spec. subarc / SAW tractor.

Any thoughts, advice and experience on learning to apply simple basic
equipment to mechanise welding?
Very open-ended question...

I can set a solid-wire GMAW / MIG with argomix shield to give say 8mm
fillet in the 2F/PB (horizontal-vertical) for a manual weld, no
problem.

I'm visualising the challenges of converting that into making metres
of unbroken smooth fillet for high-fatigue-resistance bridge
structure.

Regards,
Rich S

Jim Wilkins

2018-08-31 11:01:39 UTC

Post by Jim Wilkins

Post by Richard Smith
Hi all
Need advice "from zero upwards" about using welding tractors.
We have a bridge to make. Overbridge over a railway. Two lines.
Structurally it's typical steel bridge type - sides / "parapets" form
two main load-bearing beams, with connecting floor forming an overall
"channel" structure. With the road traffic flowing "through" /
largely within the structure.
Lots of fillet welds - but some butt, for seaming plates together.
Wish is to use welding tractor to highly mechanise the weld.
Avoid
stop/starts, promote extreme consistency of the weld runs, etc.
All
things to send the fatigue endurance way up.
Don't know what questions to start to ask...
Where do I start?
What do we develop?
Then moving into production - what's the real deal?
Etc.
Rich Smith

https://www.lincolnelectric.com/en-us/equipment/robotic-automation/Pages/automated-solutions.aspx
I've watched their automatic equipment welding hull plating in a
shipyard.

Hi Jim
Thanks and did enjoy looking at the Lincoln stuff.
That page shows robotic equipment. We are way way down the scale.
Web-search shows things like the "Esab Miggytrac B501".
Explanation - would never be weaving. Set Amps and Volts and get your
fillet in a straight run. So never need the facilities of a good
spec. subarc / SAW tractor.
Any thoughts, advice and experience on learning to apply simple basic
equipment to mechanise welding?
Very open-ended question...
I can set a solid-wire GMAW / MIG with argomix shield to give say 8mm
fillet in the 2F/PB (horizontal-vertical) for a manual weld, no
problem.
I'm visualising the challenges of converting that into making metres
of unbroken smooth fillet for high-fatigue-resistance bridge
structure.
Regards,
Rich S

Sorry, my personal experience is building small prototypes by hand,
and the local expert welders who taught me weld bridges and nuclear
piping manually.

https://www.gullco.com/shipbuilding-automation-aircraft-carrier.html

Bob Engelhardt

2018-08-31 13:02:14 UTC

...
Where do I start? ...

Anybody else find it kinda' scary that somebody who is going to be
building a _bridge_ is asking that question?

I mean that if I was going to have somebody build me a bridge with a
welding tractor, I would expect that he have extensive experience with
such a tractor; such experience then be applied to the bridge building.

Jim Wilkins

2018-08-31 15:21:29 UTC

...
Where do I start? ...

Anybody else find it kinda' scary that somebody who is going to be
building a _bridge_ is asking that question?
I mean that if I was going to have somebody build me a bridge with a
welding tractor, I would expect that he have extensive experience
with such a tractor; such experience then be applied to the bridge
building.

The lowest "qualified" bidder gets the job.

Richard Smith

2018-08-31 20:23:21 UTC

...
Where do I start? ...

Anybody else find it kinda' scary that somebody who is going to be
building a _bridge_ is asking that question?
I mean that if I was going to have somebody build me a bridge with a
welding tractor, I would expect that he have extensive experience with
such a tractor; such experience then be applied to the bridge
building.

No they don't.

They know the person is both highly qualified and significantly
experienced including with bridges - and are made further confident
that this person has a confident character and is completely at-ease
reaching-out to benefit to the limit of contemporary knowledge from
those he respects.

Richard Smith

2018-09-02 09:25:07 UTC

...
Where do I start? ...

Anybody else find it kinda' scary that somebody who is going to be
building a _bridge_ is asking that question?
I mean that if I was going to have somebody build me a bridge with a
welding tractor, I would expect that he have extensive experience with
such a tractor; such experience then be applied to the bridge
building.

No they don't.
They know the person is both highly qualified and significantly
experienced including with bridges - and are made further confident
that this person has a confident character and is completely at-ease
reaching-out to benefit to the limit of contemporary knowledge from
those he respects.

Come on people. So some of you style yourselves as so knowing and
totally up there and so able to look in judgement. Show me there's
some basis to that.

Right - we have an "Esab Miggytrac" and we've got an 8mm (5/16th-inch)
fillet in the 2F/PB/hori-vert position manually - nicely flowed-in and
wetted-in at the edges, etc. Conditions checked by macro-etch, break,
etc - all excellent by a wide margin. We put the torch in the tractor.
Hints on set-up?
Find same angles as manual?
Setting the guide-wheels (angle-in a bit, for instance?)
Things to look out for?
What differs from manual?

Yes I have some experience, but I'm looking to this vast experience
you intimate you have...

Regards,
Rich Smith

glen walpert

2018-09-20 22:36:19 UTC

...
Where do I start? ...

Anybody else find it kinda' scary that somebody who is going to be
building a _bridge_ is asking that question?
I mean that if I was going to have somebody build me a bridge with a
welding tractor, I would expect that he have extensive experience with
such a tractor; such experience then be applied to the bridge building.

No they don't.
They know the person is both highly qualified and significantly
experienced including with bridges - and are made further confident
that this person has a confident character and is completely at-ease
reaching-out to benefit to the limit of contemporary knowledge from
those he respects.

Come on people. So some of you style yourselves as so knowing and
totally up there and so able to look in judgement. Show me there's some
basis to that.
Right - we have an "Esab Miggytrac" and we've got an 8mm (5/16th-inch)
fillet in the 2F/PB/hori-vert position manually - nicely flowed-in and
wetted-in at the edges, etc. Conditions checked by macro-etch, break,
etc - all excellent by a wide margin. We put the torch in the tractor.
Hints on set-up?
Find same angles as manual?
Setting the guide-wheels (angle-in a bit, for instance?)
Things to look out for?
What differs from manual?
Yes I have some experience, but I'm looking to this vast experience you
intimate you have...
Regards,
Rich Smith

Posting as a retired old geezer with some decades ago experience with
semi-automated welding of different sorts (TIG), things to consider:

Your starting point should definitely be to attempt to duplicate your
known good manual weld process as closely as possible.

Next run a series of tests to determine your "process window" on key
parameters such as tractor speed, voltage, torch angle, - find the limits
on travel speeds (high and low) which produce a satisfactory weld on each
of several voltage settings around normal for a manual weld, possibly
varying torch angle also.

(You should be able to find the process window for the guide wheel
settings before doing any welding.)

Now you can take a conservative approach and run in the middle of the
acceptable process window for maximum tolerance to errors, or you can
decide to push the fast (economical) end of the window within some
reasonable margin of the limits. Typically a mechanized welding process
can be pushed faster than manual because the machine is steadier than the
hand.

You may run into issues with poor fit-up requiring manual adjustments to
accommodate varying groove widths, etc. (Min/max groove width could be
part of your process window testing.) You will still need constant
monitoring by someone who knows how to do the weld manually and can
identify and fix problems as they occur, but this level of automation can
definitely up production rates and reduce defects.

Glen

Richard Smith

2018-09-21 20:01:32 UTC

Post by glen walpert

...
Where do I start? ...

Anybody else find it kinda' scary that somebody who is going to be
building a _bridge_ is asking that question?
I mean that if I was going to have somebody build me a bridge with a
welding tractor, I would expect that he have extensive experience with
such a tractor; such experience then be applied to the bridge building.

No they don't.
They know the person is both highly qualified and significantly
experienced including with bridges - and are made further confident
that this person has a confident character and is completely at-ease
reaching-out to benefit to the limit of contemporary knowledge from
those he respects.

Come on people. So some of you style yourselves as so knowing and
totally up there and so able to look in judgement. Show me there's some
basis to that.
Right - we have an "Esab Miggytrac" and we've got an 8mm (5/16th-inch)
fillet in the 2F/PB/hori-vert position manually - nicely flowed-in and
wetted-in at the edges, etc. Conditions checked by macro-etch, break,
etc - all excellent by a wide margin. We put the torch in the tractor.
Hints on set-up?
Find same angles as manual?
Setting the guide-wheels (angle-in a bit, for instance?)
Things to look out for?
What differs from manual?
Yes I have some experience, but I'm looking to this vast experience you
intimate you have...
Regards,
Rich Smith

Posting as a retired old geezer with some decades ago experience with
Your starting point should definitely be to attempt to duplicate your
known good manual weld process as closely as possible.
Next run a series of tests to determine your "process window" on key
parameters such as tractor speed, voltage, torch angle, - find the limits
on travel speeds (high and low) which produce a satisfactory weld on each
of several voltage settings around normal for a manual weld, possibly
varying torch angle also.
(You should be able to find the process window for the guide wheel
settings before doing any welding.)
Now you can take a conservative approach and run in the middle of the
acceptable process window for maximum tolerance to errors, or you can
decide to push the fast (economical) end of the window within some
reasonable margin of the limits. Typically a mechanized welding process
can be pushed faster than manual because the machine is steadier than the
hand.
You may run into issues with poor fit-up requiring manual adjustments to
accommodate varying groove widths, etc. (Min/max groove width could be
part of your process window testing.) You will still need constant
monitoring by someone who knows how to do the weld manually and can
identify and fix problems as they occur, but this level of automation can
definitely up production rates and reduce defects.
Glen

{thumbs-up}
Much appreciated.
Thanks for benefitting me with this concentrated summary of your experience.
Rich S

Richard Smith

2018-09-25 08:13:35 UTC

Post by glen walpert

...
Where do I start? ...

Anybody else find it kinda' scary that somebody who is going to be
building a _bridge_ is asking that question?
I mean that if I was going to have somebody build me a bridge with a
welding tractor, I would expect that he have extensive experience with
such a tractor; such experience then be applied to the bridge building.

No they don't.
They know the person is both highly qualified and significantly
experienced including with bridges - and are made further confident
that this person has a confident character and is completely at-ease
reaching-out to benefit to the limit of contemporary knowledge from
those he respects.

Come on people. So some of you style yourselves as so knowing and
totally up there and so able to look in judgement. Show me there's some
basis to that.
Right - we have an "Esab Miggytrac" and we've got an 8mm (5/16th-inch)
fillet in the 2F/PB/hori-vert position manually - nicely flowed-in and
wetted-in at the edges, etc. Conditions checked by macro-etch, break,
etc - all excellent by a wide margin. We put the torch in the tractor.
Hints on set-up?
Find same angles as manual?
Setting the guide-wheels (angle-in a bit, for instance?)
Things to look out for?
What differs from manual?
Yes I have some experience, but I'm looking to this vast experience you
intimate you have...
Regards,
Rich Smith

Hi Glen

That job ended before it even started - I never saw the railway bridge.

I will treasure the advice you gave - because that is what it is worth
for sure - and will be ready in the next job where I have long
weld-runs and / or requirement to use a "tractor".

Best wishes,
Rich Smith

Henry Mateo

2023-05-02 06:03:36 UTC

Welding a tractor for a 2-line railway span is an important and difficult task that takes a lot of skill and accuracy.

To make sure the bridge is safe and the structure is sound, you need to know a lot about how to build and how the bridge is put together

--
For full context, visit https://www.polytechforum.com/welding/welding-tractor-for-bridge-2-lines-railway-span-54167-.htm

Snag

2023-05-02 18:57:43 UTC

Post by Henry Mateo
Welding a tractor for a 2-line railway span is an important and
difficult task that takes a lot of skill and accuracy.
To make sure the bridge is safe and the structure is sound, you need to
know a lot about how to build and how the bridge is put together.

You need to go back to the kiddy pool , Henry . Rich is probably one of
the most experienced weldors on this USENET NEWSGROUP - screw polytech ,
they're stealing content and representing it as their own product . I've
read most everything Richard has posted and while I didn't understand a
lot of what he wrote , what I did understand has made me a better weldor .

--
Snag
"You can lead a dummy to facts
but you can't make him think."

Jim Wilkins

2023-05-02 20:43:09 UTC

Richard Smith

2023-09-03 21:47:09 UTC

Post by Snag

Post by Henry Mateo
Welding a tractor for a 2-line railway span is an important and
difficult task that takes a lot of skill and accuracy.
To make sure the bridge is safe and the structure is sound, you need
to know a lot about how to build and how the bridge is put together.

You need to go back to the kiddy pool , Henry . Rich is probably one
of the most experienced weldors on this USENET NEWSGROUP - screw
polytech , they're stealing content and representing it as their own
product . I've read most everything Richard has posted and while I
didn't understand a lot of what he wrote , what I did understand has
made me a better weldor .
--
Snag
"You can lead a dummy to facts
but you can't make him think."

Belated comment and response.

I would like to dedicate much to the mentoring of the late Randy
Zimmerman.
Who contributed much to this group.
We continued in private communications.

He mentored me from the late 1990's until he died a couple of years
ago.

I did meet him in-person in late 2008. Flying into Vancouver, I
realised I had no idea what he looked like, so I emerged in the
arrivals hall holding up a sign saying his name - and there he was
approaching me.

I have been there thinking "I could ask Randy how you actually do
this" then I have to think no, that is now lost and I have to survive
on what I know so far and make up the rest as I go along.

I feel grateful to the Zimmerman family who accepted / indulged Randy
advising me, and I owe a lot to him. As in - in all aspects of what
is around me which bring me joy I owe a lot to how he gave me the
means to create a life by simply doing, and the grand picture took form
out of the activities and where it meanderingly took me.

Ernie Leimkuhler deserves mention.
His own clear-thinking take on things.
Glad my writings managed to bring him amusement.

I've had other mentoring coming from totally different places. On
fatigue that came to me from someone who was a voice on the end of the
phone when I dialed, and he talked me through the progression of my
tests. From the most elementary replications of the most basic,
through to thrusting my investigations along novel paths.

But anyway, may I dedicate to the late Randy Zimmerman and wish well
to his family wherever their paths have lead them.

Regards to all

Jesse Bear

2018-09-17 15:18:50 UTC

...
Where do I start? ...

Anybody else find it kinda' scary that somebody who is going to be
building a _bridge_ is asking that question?
I mean that if I was going to have somebody build me a bridge with a
welding tractor, I would expect that he have extensive experience with
such a tractor; such experience then be applied to the bridge building.

No they don't.
They know the person is both highly qualified and significantly
experienced including with bridges - and are made further confident
that this person has a confident character and is completely at-ease
reaching-out to benefit to the limit of contemporary knowledge from
those he respects.

Agreed. I am very skilled at what I do, and I often find myself being asked to consult on projects which include elements outside my field(s) of expertise. If I were less secure in my knowledge and experience, I might be afraid to ask what could sound like very basic questions, and have to pass on otherwise good work opportunities.

For instance, remember a couple of years ago when I was asking (here) some pretty rudimentary refrigeration questions? That system is now running better than it has in the 30+ years for which I have logbooks. I am now consulted by others in the field as an expert.

You don't learn everything in a classroom.

Richard Smith

2018-09-20 00:52:03 UTC

Post by Jesse Bear