Current Swivel Mechanism The current set up has a roller rolling on a conical plate to allow the boom to rotate. This was too complex and had too many parts thus it was re-designed to work with the new cross member. This old design was the trunnion rest model. A new mechanism was done up … Continue reading The Re-Design: Swivel Mechanism (Pt. 3 of 4)
Tag: Science & Technology
The Re-Design: The Cross-member (Pt. 2 of 4)
The first part that was re-worked was the upper parts of the crossmember, the boom attachment is now a single flat plate that bolts onto the boom. This is now welded to the cylindrical section that makes up the cross member. New upper cross-member However we can see that the Material still has some stresses … Continue reading The Re-Design: The Cross-member (Pt. 2 of 4)
The Re-Design (Pt. 1 of 4)
The re-design, means that we have to find a way to get the cross member to handle the loads as well as be dis mantled. It must still bolt to the boom and at the roller rest stop is should allow the member to rotate along the rest stop. The current arrangement uses regular shapes … Continue reading The Re-Design (Pt. 1 of 4)
Upper Span Assembly & Re-Design
The upper span assembly forms the part the overall assembly that connects the boom to the cross member and then on to the brace. This piece is simple enough a simple T shape with 3 holes that position it at a 45deg to the boom when assembled. However at 11.113mm thick it still can not … Continue reading Upper Span Assembly & Re-Design
Crane : Boom Bracket
Original Design The original design was tested with 37.812kN of force in a downward direction with Armstrong 240 as the material of choice. Right of the bat we see that it is clearly unsuitable, with a maximum stress of 999.5MPa located primarily along the vertical members of the design spreading outward from that. Note that … Continue reading Crane : Boom Bracket
Crane : Boom (Pt. 2 of 2)
The design going forward had holes drilled into the rear so as to a fix it to the turntable as well as holes drilled to accommodate the mounting of the cross-member. This geometry introduces new points for stress concentrations as such this increases stresses which may necessitate redesign or the selection of a new material. … Continue reading Crane : Boom (Pt. 2 of 2)
Crane : Boom (Pt. 1 of 2)
Now the boom has been adjusted, with the overall design having a cross-member, this introduces new forces and geometries that have to be better taken into consideration. The initial design while demonstrating the basics when applying "the math" (number & formulae) is rather simple not taking into account all the forces at work. The modified … Continue reading Crane : Boom (Pt. 1 of 2)
Cranes : The Trolley (Pt. 1 of 2)
The trolley is the part to which the load is attached to, the trolley also allows for the load to traverse the length or at least a prescribed part of the boom. The load doesn't have to attach directly to the trolley, the trolley can by means of bolt holes can accommodate a motorized winch, … Continue reading Cranes : The Trolley (Pt. 1 of 2)
Crane : Swivel Mechanism (Pt. 3 of 3)
Basic sketch of swivel assembly The swivel mechanism has 3 sections, the upper middle and the lower. The upper section attaches to the I beam boom by way of 4 bolts. The middle section sits between the upper and the lower preventing any contact thus allowing free rotation of the upper. This section is ultimately … Continue reading Crane : Swivel Mechanism (Pt. 3 of 3)
Crane : Swivel Mechanism (Pt. 2 of 3)
The bearing can be made smaller however this would increase the complexity of the mounting mechanism as one would have to be designed to hold the bearing within the mast, by keeping the bearing larger than the mast diameter means that it can fit atop the mast with a lot less modification, or a the … Continue reading Crane : Swivel Mechanism (Pt. 2 of 3)
Crane : Swivel Mechanism (Pt. 1 of 3)
When designing the crane it was necessary for the boom to be able to swing, this adds to its utility allowing it to be better able to lift and move objects over a greater range. The first and simplest mechanism would be a pin hinge and a bushing, this would be the simplest. The bushing … Continue reading Crane : Swivel Mechanism (Pt. 1 of 3)
Crane : The Mast
The mast in this case is the free standing vertical column that that the boom will be cantilevered of. The upper portion of the mast will have the mechanism to allow the boom to rotate, and the lower portion will allow for the crane to be secured to the ground. The basics of the mast … Continue reading Crane : The Mast
Crane : Stress & Deflection
Beam Selection After the continuous trial of different beams, the beam with the appropriate 2nd moment of area is chosen. For selecting the beam we look at the flange width and the beam height. The 3rd factor to consider the beam weight. From the chart on the left we can see that as the beam gets … Continue reading Crane : Stress & Deflection
Crane : The Cross Member
The section we are referring to is E-B, at the point E the joint is fixed to the base of the boom, this allows for the section to move with the boom. At this point, B, their will still be an upward, lateral and resultant force. The member E-B is 2.121m long, and will be … Continue reading Crane : The Cross Member
Crane : Material Selection
Material selection is influenced in BOTH cases by the calculation of the stresses and then applying a safety factor, in this case 2.0, to the stress or to the yield or proof strength. If the safety factor is applied to the stress it is multiplied, this value must still be below the yield or proof … Continue reading Crane : Material Selection
Crane : The Freebody (Pt. 3 of 3)
The new freebody has details that were not included in the original, the first is to the upper boom section , with the addition of the diagonal strut E-B. This was put to help with overall beam deflection. This works by shortening the length of the beam. In calculation the length of the beam was … Continue reading Crane : The Freebody (Pt. 3 of 3)
Crane : The Freebody (Pt. 2 of 3)
The completed freebody has not just the plan of forces and the location of them but has the position of expected cross-members. This freebody will be used to properly and fully calculate the extent of forces acting on the various sections and cross-members of the jib crane. This involves breaking up the jib crane into … Continue reading Crane : The Freebody (Pt. 2 of 3)
Running Casing
Pre-running procedures Always pre-plan Ensure proper layout on the rig rack Joints need to be laid out properly especially when dealing with different weights of casing in one run. Clean the threads. Once the thread protectors are removed the threads should be cleaned. The tubular interiors should be inspected. Handling procedures Use thread protectors Use … Continue reading Running Casing
Wellbore Tubulars
Casing hanger – this is installed to support the individual casing strings in the well. This is the landing base or casing head. This is usually welded or screwed to the top of the surface casing string. The surface casing string serves as a foundation pile for the well. This transfers the hanging load to … Continue reading Wellbore Tubulars
A Guide to Reaming
Always Plan your tripping schedule: Record tight spots from previous trips Know the wellbore geometry; the deviation, doglegs etc. maintain constant communication with your directional personnel. Despite pulling up always be prepared to run downward. This may be needed to free the pipe after a connection. One example is the consistent execution of 200 to … Continue reading A Guide to Reaming