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Re: Runway beam expansion details

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 May I suggest a consultation with a crane expert?  Try calling or
writing
 Jim Corns at Crane Pro Services in Santa Fe Springs, CA.  Crane Pro is
the
 service division of Kone Crane International.  He is the most
 knowledgeable person I know when it comes to industrial in-plant cranes
and unique
 installations.  He can be reached at 800-854-5663.  His email address is
 jim.corns(--nospam--at)kcinet.com.  I seriously doubt he would ever charge for a
 telephone consultation, and he would likely travel to your site to
market
 Crane Pro Services. Tell him Russ Nester refered you.  Good luck, and
please
 share the final result with us all.
 
 Russ Nester, SE, GE
 rnester(--nospam--at)juno.com
 __________________________________
> > Stan Mulder wrote:
> > > 
> > > Thanks for your reply. I was however referring to underslung
trolleys
> > > carrying a hoist. The trolley is running suspended off the bottom
> > flange and
> > > has to run over a 1.25 ins expansion joint. The crawl beam in
question
> > is
> > > spanning between Boiler Units in a power station. The units are
> totally
> > > independent and have expansion gaps between the units.
> > > 
> > > I don't think that there is a connection devised for expansion
joints
> > in
> > > crawl beams ? The bottom flange is subjected to cross bending and
the
> > > trolley wheel needs to be continuously supported.  The small wheels
> (~5
> > to 6
> > > ins diameter) also cannot move over gaps larger than about 1/8 ins
> > otherwise
> > > the gap interferes with the with the movement. The flanges also
need
> to
> > be
> > > perfectly level at joints. Mitring the flange tends to weaken the
> > flange in
> > > cross bending because the wheels are close to the edges of the
flange,
> > with
> > > a impact load applied at the tip of the taper.
> > > 
> > > It is often necessary to reinforce the bottom flanges at the joints
> but
> > even
> > > if this is possible, I dont think that it will overcome the other
> > problems.
> > > The other option would be to make the crawl continuous and
providing
> > > longitudinal sliding connections in the top flange support
> connections.
> > > However these sliding connection would have to be very free moving
> even
> > > under load. I don't feel comfortable doing this.
> > > 
> > > I would  appreciate any responses.
> > > 
> > > Thanks.
> > > -----Original Message-----
> > > From: Blomberg, Paul <Paul.Blomberg(--nospam--at)Jacobs.com>
> > > To: seaint(--nospam--at)seaint.org <seaint(--nospam--at)seaint.org>
> > > Date: 04 February 1999 10:58
> > > Subject: RE: Runway beam
> > > 
> > > >I normally provide the expansion joint in between beams and allow
the
> > crane
> > > >rail to span over the expansion joint.  Then, within a few feet of
> the
> > > >structural steel expansion joint, I cut a 60 degree angle on the
rail
> > to
> > > >allow the expansion there.  The angle cut allows the expansion but
> > > maintains
> > > >positive bearing between the crane wheel and crane rail.
> > > >
> > > >It's an old detail.  There may be better approaches.
> > > >
> > > >Paul F. Blomberg
> > > >Jacobs Engineering Group
> > > >Phoenix, AZ
> > > > ----------
> > > >From: Stan Mulder
> > > >To: seaint(--nospam--at)seaint.org
> > > >Subject: Runway beam
> > > >Date: Thursday, February 04, 1999 12:15PM
> > > >
> > > >What details are suitable for overhead crawl beam expansion
joints.
> > Usually
> > > >gaps at joints should be kept as small as possible (2 mm or say
1/8
> > ins) to
> > > >enable the trolley wheel to pass smoothly over the joint.
Sometimes
> it
> > is
> > > >necessary to use a long crawl and introduce expansion joints.
> Possible
> > > >cutting the bottom flange at 45 degrees and reinforcing the bottom
> > flange.
> > > >How big can this gap be (3/8 ins) ? Is there some way of making
the
> > gap as
> > > >large as 1 ins ?
> > > >
> > > >Thanks..
> ___________________________
> > I just joined the seaint broadcast group and noticed your email.
> > 
> > Is the trolley BEAM expanding/contracting, or the supporting
structure? 
> > If it's the supporting structure, why not make the beam continuouse
and
> > design the supports/hangers to allow movement, similar to pipes which
> > expand/contract?
> > 
> > Longitudinal movement could easily be accommodated by using "link"
type
> > hangers which are pinned at each end.
> > 
> > Hope this helps.
> > 
> > Laurence Oeth
> > PE - Oregon
> > 
> 

--------- End forwarded message ----------

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