Experience

The overall design of our crane was simple and could sustain in the adverse conditions as mentioned in the tender. I personally feel, we could have designed it better, if we were given little bit more time. I apologise for not updating the blog on time. Unfortunately, the main reason behind this was my injury, because of what I was on bed for more than 4 weeks. As I did not have internet access, I could not do any work while I was on bed. After four weeks, I could walk with crutches, but was left behind in other modules too. As I feared to do badly in other modules too, I tried to put my efforts to catch up on everything I missed. Even though, I had short span of time to work towards this project, it was a good experience to use the available information around us and virtually manufacturing something very important from scratch.

Conclusion

Overall I am not pleased with the outcome of this project; it could have been a lot better. The lack of commitment of certain individuals caused a major setback to the project. The quality of the crane could have been improved in many aspects. This was a disappointing project and if I were to do it again, I would do things a lot differently.

Costs

As according to the calculations, the total volume of HSLA steel used is 18.084*10^(-3) m^3 and cost of 1 m^3 is £ 35277.77.

So, therefore the cost of the total HSLA steel to be used is = 35277.77*18.084*10^(-3) GBP

= £637.96

Cost of the manufacturing of special I-Beam = £100

Cost of 16 nuts and 16 bolts is as follows;

Cost of A2 stainless steel M12*110mm bolts = £ 19.50

Cost of A2 stainless steel M12 hex nuts = £ 2.70

Cost of chain hoist = £ 150.49

Cost of rollers = £ 48.69

Cost of rubber sphere = £20.99

The total cost of crane comes out to be £ 980.33. As this is the cost of single K-crane, the cost per crane can be brought down depending on the number of cranes ordered.

The selling price of this crane is £1349.99 giving us the profit of approximately £370 per crane. Assuming, if we get the order for 100 cranes, we can easily make profit more than £37,000.

Total Volume of Steel Used

1.) Volume of the top sheet = 5*0.08*0.005m^3 = 0.002 m^3
Volume of the both sheets = 2 * 0.002 m^3 = 0.004 m^3

Volume of vertical sheet = 10*10^(-3)*190*10^(-3)*5 = 0.0095m^3
Total volume of the top beam = Sum of the volumes two parallel sheets and vertical sheet
= (9.5+4)*10^(-3) m^3 = 13.5 * 10^(-3) m^3

2.) Now, In this part we would calculate the volume of the rectangular bars,
Height of the bar = 1.06 m
Breadth of the bar = 50 mm
width of the bar = 50 mm
, therefore the volume of this bar = 1.06*0.05*0.05 m^3
= 2.65 * 10^(-3) m^3
Since this bar is hollow from inside, we would calculate the volume of unoccupied space
= 1.06*0.04*0.04 m^3 ( the thickness is 5 mm)
= 1.69*10^(-3) m^3

The original volume occupied by HSLA steel = (2.65-1.69)*10^(-3) m^3
= 0.96*10^(-3) m^3
As the total no. of bars used in this gantry crane is 2, so multiplying the result by 2, we get
= 2*0.96 *10^(-3) m^3 = 1.92*10^(-3)m^3


3.) Here we will determine the amount of material used i.e. the volume of the four hollow legs used in this crane.
Height of the rectangular bar = 0.74m
Width of the bar = 50mm
breadth of the bar = 50mm
Volume = 0.74*0.05*0.05 m^3
= 1.85 * 10^(-3) m^3
Since the thickness of the steel is 5 mm, therefore in this case the breadth and width becomes 40 mm.
The volume of the space with these dimension = 0.74*0.04*0.04m^3
= 1.184*10^(-3) m^3
The volume of the steel used in this bar = (1.85-1.184)*10^(-3) m^3
= 0.666*10^(-3) m^3
Now, the number of these bar legs used = 4
The total volume of the HSLA steel used = 4*0.666*10(-3)m^3
=2.664*10^(-3) m^3

4.) Volume of the spheres used = 4*4/3*3.14*((0.15/2)^3) m^3
= 4*1.767*10^(-3) m^3
= 7.068*10^(-3) m^3
The material used for these spherical balls is volcanic rubber which would give the crane extra stability on uneven ground.

According to these calculations, the total volume of the HSLA steel used = 18.084*10^(-3) m^3

Main Beam Final Calculations

These calculations show the final dimensions for the main beam cross section that we settled on. The I value is finalised and the maximum stress and maximum deflection are calculated to be comfortably below the threshold that we decided.

Weight of Main Beam

An estimated weight of 105.3kg is established for our main beam. We consider this to be a weight that can be carried by multiple people over 100m and carried by vehicle.

A further consideration is that the ends of the beam could be made smaller as shown in the diagram at the top of the picture. As most of the stress and weight is centred in the middle of the beam, the ends wouldn't need to be as thick and weight of the beam could be minimised in this way.

Main Beam Further Calculations

These calculations provide different values of I by using different dimensions for the cross-section.