How to Measure for an Overhead Crane’s Runway Rail Size & Craneway Length
Understanding how a new crane will fit into your present facility, as well as how existing runway and support structural and design considerations can be utilized.
It's always a good idea to understand the basic design requirements and specifications of a project before adding a new overhead crane or potentially replacing an existing crane in your production or manufacturing facility.
It will be easier to lay out the design criteria and expectations for any crane manufacturer who bids on the project if you have a clear grasp of the space available in your building, the existing building supports that the crane can be put on, and any overhead obstructions.
It's possible that you already have runways in your building. It's possible that you moved into a facility that had an overhead crane earlier and that the original support structure is still in place, and you're adding a new crane, replacing an existing crane, or upgrading or modernizing a crane on an existing runway system.
It's also feasible that this is a brand new overhead crane set up at a new construction facility or an existing structure.
In any case, before meeting with an overhead crane manufacturer, you should familiarize yourself with the following measurements:
- Runway beam size
- Runway rail size
- Crane span
- Runway length and distance between runway supports
- Building clearances
The more information you can acquire ahead of time, the more information the crane manufacturer will need to send back to their technical team in order to put together an appropriate price and project specification.
Furthermore, the better you grasp the design and specification requirements for your own crane system, the better prepared you will be to assess the various quotes you receive against the project objectives.
Measure the Crane's Runway Beams
Ideally, you'll be able to use a lift or a neighboring mezzanine to get closer to the runway beams (if available). If you don't have a tape measure or a laser pointer, you can get a lot of these measures using a tape measure or a laser pointer.
If you have easy access to the runway beam, taking measurements of the actual runway beam is as simple as running your tape measure from the bottom to the top. If you can't get to the beam, stand beneath it and use your laser pointer to measure the top flange, then measure the bottom of the beam and deduct the difference. This will give you the height of your beam. If you can get close enough to the beam, you can measure the width and thickness of the flanges.
Getting measurements for the width of the flange, toe, and thickness of the cap will also help the engineering team understand the crane's design needs if the runway beam has a cap channel added for further reinforcement.
Measuring the Crane's Rail Size
Making sure you know how big the rails are will help you size the wheels correctly. The head width and rail height are the two most significant dimensions for crane rails. This enables the technical team to establish the rail size and what size wheels should be utilized on the crane system. This is significant for two reasons: first,
For appropriate alignment and tracking of the crane as it moves down the runway, match the size of the wheels to the size of the rails. This can assist protect the rails and wheels, as well as the beams and structural supports, from premature or excessive wear.
A properly sized wheel will eliminate runway rail design revisions, allowing the customer to keep the original structure in place. If the runway beams and rails can be reused, this can save the customer a lot of money.
Standard crane runway rail
Runway with cap
Rail Width (A) Runway Beam Chart (B) Width of the rail head (C) Height of the rails (D) Beam Height on the Runway (E) Flange Width of Runway Beams (F) Flange Thickness of Runway Beams (G) Toe Channel Cap (H) Width of the channel cap
Measuring the Crane's Runway Length and Distance Between Supports
Consider the length of your runway and the number of building column supports available to support the crane's deadweight and load.
The whole overall distance that the crane will travel across the facility is measured by the runway length. Use the building's specifications, the layout of your existing production space, or sketch out or mark off an area you wish to be able to use for material handling and load transportation to get a good idea of how long it will be.
You'll also need to figure out how far apart the building supports are that the runway beam will go between. To do so, align your laser against a building support beam and measure the distance between the runway beam and the next support.
Crane runway inspection and maintenance
Full runway inspections and assessments are sometimes an afterthought when users of overhead cranes and hoists seek world-class safety, operation, and condition assessments on their cranes and hoists. This assumption is based on the idea that runways are static and will last for many years without requiring any maintenance or inspections. In fact, runways are dynamic and necessitate careful inspection and condition evaluation to ensure proper safety, trouble-free operation, and the crane's as well as the runway rails' longevity.
Seasonal expansion and contraction strains on runways, columns, and fasteners are produced by temperature changes from cold in winter to hot in winter. When the runway is supported by the building structure and columns, as well as when the runway structure is independent and just tied back to the building, these stresses occur. The alignment of runways and columns, as well as the strains on runway tiebacks, are affected by expansion and contraction forces. Tiebacks are prone to breaking over time due to structural movement and vibrational pressures caused by crane operation. Broken tiebacks cause runway alignment issues as well as increased loads on runway beams, which can lead to crane damage or even structural failure.
Frictional pressures from the operation of bridge cranes on the runways produce routine wear on the runway rail. Cranes that are poorly spanned or misaligned can cause rapid runway rail wear, which must be rectified soon in order to maintain the runway rail's proper operating life. The cost of replacing extended stretches of runway rail due to misaligned runways or cranes is sometimes higher than the cost of replacing the bridge cranes themselves. Vibration from crane operations also loosens fasteners on runways, columns, crane rails, and end stops. These unsecured fasteners frequently fall from ceiling level heights, posing a substantial risk of head injury to anyone working below.
To check a runway properly, the inspector must have access to see and physically inspect both sides of the runway, as well as the columns and runway girders. If access to the runway is hampered by equipment on the floor or inventory, adequate fall protection measures must be provided above the runway beams to allow the inspector to safely walk the runway.
A proper through routine crane runway inspection must be conducted at least annually and should include the following.
- Check the whole length of the runway rail for abnormal or excessive wear on the head and sides.
- Look for loose hardware in each component of the rail fastening system.
- Examine the condition of runway splices and end stops, as well as their fasteners.
- Examine the condition of the end-stop bumpers.
- Examine the structural beams, columns, and shelves or haunches on the runway, as well as any attachment hardware.
- Examine the condition of all runway tiebacks and the hardware that holds them in place.
- Any structural bolts that have become loose must be replaced and torqued correctly according to AISC specifications.
- A rail alignment and crane alignment survey should be conducted to determine the source of significant runway rail deterioration.
As you can undoubtedly see, a proper runway inspection cannot be completed in the time provided for a standard crane inspection and must be treated as a separate item that requires the appropriate amount of time based on access and runway length.
Article by Bella ，who has been in the hoist and crane field since 2016. Bella provides overhead crane & gantry crane consultation services for clients who need a customized overhead travelling crane solution.Contact her to get free consultation.
