I hear what you're
saying, Ralph; but down time for a factory can be pretty expensive too.
But it's the owner's money and he should be the one to decide whether or not to
provide for a future crane.
I think what I would do
in this case (with the owner's approval, of course) is construct a standard
floor trench designed and supported to function as a foundation grade beam
for the crane, provide a steel plate cover, and leave the rest to the
future crane supplier to drill anchors as required for whatever crane rail slide
plate detail they want to use to secure any reasonable ASCE rail size they might
H. Daryl Richardson
----- Original Message -----
Sent: Thursday, April 19, 2007 4:29
Subject: Re: Gantry Crane Rail
I don't mean this as any sort of criticism of
anyone, but this discussion reminds me of a situation that occurred in a
transit tunnel under downtown Seattle a few years ago: Planning for
future light rail the designers embedded rails in the tunnel floor, even
though initial use was only by buses. When the time came to activate the
rails they were found to be inadequate (electrically, for signaling/control
purposes IIRC), requiring multi-million-dollar replacement.
In a message dated 4/19/07 2:45:06 PM,
Thanks for the information. I
am specifying a 20 ton crane capacity and there will be worker and forklift
traffic across the rail so I'm embedding the track. Unfortunately, it
is a "future" gantry crane so we don't have an awarded supplier and the
manufacturers are a little slow providing specific information if there is
no sale in sight.
So I'm fishing for a generic block out detail
that can be installed now and removed in the future and a gantry crane rail
installed. All the discussion I get on the subject is good for
On 4/19/07, Daryl Richardson <h.d.richardson(--nospam--at)shaw.ca>
assessed, reviewed, and/or designed a few gantry cranes over the
years. Following are a few thoughts that may (or may not) be
helpful. You are welcome to the helpful
considerations are probably the load rating and type of wheels you want
to use. Some gantry cranes I have been involved with have been on
castors, hence, they could be moved anywhere in the building even when they
were loaded. No rails required! These have included cranes up to
two ton rating.
intermediate cranes (say three ton to seven or possibly ten ton) you
could consider using solid rubber wheels which do not require a rail but
probably do require a dedicated runway location in order to have adequate
foundation to avoid cracking the slab.
For larger design loading, say above seven or ten
ton, you will probably opt for a rail system. Whether you use a
block-out or not is another question. this, of course brings up the
question "do you use a solid bar for a rail or do you go to an actual ASCE
rail?" This will affect what type of block-out, if any, you
indicated why you need a block-out. I'm speculating that you want to
avoid a tripping hazard or provide some type of cross rail access for a
vehicle or a dolly or some other wheeled transporter. If you can use
the solid bar rail you can probably use a channel cast into the floor toes
up (either a C or an MC shape) according to the depth you
require. I'm sorry; I don't have a detail for a larger cast crane
Hope this is
H. Daryl Richardson
what's free at http://www.aol.com.