Archive for March, 2015

Roping a Crane

The initial installation of the rope to your equipment is most important. High performance wire ropes can be damaged from induced twist through incorrect installation. An extreme circumstance may mean discard of the rope.

The rope, when installed to your equipment, must be reeled correctly.

OVER WOUND DRUM: If installing onto the top of your machinery drum, the rope must be reeled from the top of the reel under a constant maintained tension.

UNDER WOUND DRUM: If installing onto the bottom of your drum, the rope must be reeled from the bottom of the reel with a constant maintained tension.

The rope should not be allowed to uncoil with loose wraps on the reel.

An easy way to remember the correct installation method is:

TOP TO TOP        BOTTOM TO BOTTOM

To not maintain a constant tension during installation can induce twist into the rope and your reeving system, or worse, the rope could become kinked, possibly rendering the product unsuitable for service.

rope cranes101 pic 1

Do not install the rope directly to the rope drum without tension being applied.

For tensioning, we recommend 1 to 1-1/2% of the minimum breaking load (mbl) of the rope.

35 ton mbl x 1-1/2%  = approximately 1/2 ton tension required.

80 ton mbl x 1-1/2% = 1.2 ton approximate tension required.

rope cranes101 pic 2

Fleet Angle: To install with greater than a 1-1/2º (degree) fleet angle can induce excessive twist or rotation into the rope. Please beware of the importance of correct alignment of the reel to sheave or drum for installation purposes. High performance rotation resistant ropes can be susceptible to problems from twist induced at installation. Refer to the diagram below.

The twist of a rope at 1º fleet angle and at 5º. Twist becomes induced due to the rope not entering the sheave [etc] at the lowest point, (that point being the sheave groove), first touching the flange then rolling into the bottom of the groove.

The rolling action caused by excessive fleet angle twists the rope. This negative effect is further accentuated when multi-part reeving systems are used.

 

 

 

 

Tennessee River Walk

This week, President of Cranes101, Jay Sturm, spent some time in Chattanooga, TN. He was working on a consulting case for an accident investigation. But he managed to rustle up some down time, and spent it site seeing! While enjoying a stroll along the Tennessee River, he stumbled upon a Link Belt LS that was driving sheets onto the shore line. You can see the river boat int he background.

cranes101 lattice boom chattanooga

Here, Jay poses by the River tours. We’re glad our boss got to soak up some sun before returning to Massachusetts today where, of course, we’ll be having more snow tonight. Oh well, all good things must come to an end.

jay cranes101 chattanooga

 

Until next time!

Did You Know? Swing Assembly:

The swing assembly that is usually buried in the pedestal of a boom truck, bucket truck or digger derrick is often times mounted output shaft up.

When the output shaft is facing up is has the ability to fill the rotation gearbox with water. Once you have water in the gearbox it’s just a matter of time before it destroys all the components in the gearbox.  This problem can get quite pricey.

There’s a couple of telltale signs that will help you determine if there’s a possibility of a problem. One sign is if there is gear oil dripping down from the swing motor or maybe even from the swing limit lever shaft. If you see gear oil then it’s likely that the gearbox has been pressurized by a faulty seal in either the swing motor or brake. This can affect the output shaft seal and lead to the seal allowing water into the gearbox.

The sooner something like this is fixed, the cheaper it will be.

swing assembly cranes101 pic 1

Above: a view of the swing motor from the right side of a National boom trucks pedestal.

Below:  a view of the swing motor, brake and gearbox on the same crane from the left side of the pedestal. It’s carefully hidden behind the hoses

 

 

swing assembly cranes101 pic 2

Congrats to CATS!

CATS logo Our picture of the week this week is dedicated to our sister company, Cranes Aerial Truck Service (CATS). This week, they reached their 20,000th inspection since opening in 2001. We are so proud of all the hard work they have put in over the years.

Our inspectors are the best in the business. They work 7 days a week, in the heat of the summer, frigid winter, before the sun comes up and long after the sun goes down. Our inspectors travel all over the country to provide thorough, honest, and efficient true third party inspections wherever our customers need us to go!

And of course, we can’t forget to congratulate the support team that is in the office, providing top of the line customer service to over 2,000 companies of all shapes and sizes; from municipalities, general contractors, delivery companies, steel erectors, concrete/precast, and of course, construction companies.

There’s nothing this team can’t handle.

For more information on having a third party inspection done, please call 866-788-7600. You’ll be glad you did!

 

Can You Spot the Mistake?

A quick lesson on Crane Levels.

Is your crane level? First you must ask yourself, is your level level.

A level placed vertically on equipment is as useful as broken watch.

Direct center of this picture is a crane level. July 2004 newsletter

Until next time!