Assignment - Marine Infrastructure and Port Design
Assume that a recent earthquake has destroyed the existing deep water port located on a Pacific Island and only a small port which can take up to 10 m draft vessel has survived. This port is the lifeline to the country. It is expected that between 200,000 to 600,000 TEUs of cargo will be imported over the next 10 years for the reconstruction effort. Cargo would be coming from different countries in various quantities and will need to be transhipped to the aforementioned island from a larger neighbouring port.
Port Relief which is strategically located in relation to the main trade routes in a neighbouring country has been selected for transhipping cargo to the aforementioned island. You are the Port Engineer of Port Relief and you are called to assess the situation and make recommendations for upgrading the existing 20 year old deepwater wharf to cater for mother ships of 5000 to 7500 TEUs capacity for transhipping containers to the country. For transhipment it is intended that 1500 - 2000 TEU capacity daughter ships would be used because of the draft limitations in that country.
The existing wharf is only 150 m and it is expected that this will be adequate for meeting the requirement in that country. The existing wharf structure is in need of substantial remedial works but needs to be assessed and strengthened for the larger vessels. In addition the fender system will need to be changed to handle the larger vessels and the smaller range of vessels. You have to assess the size and quantity of fenders that will need to be pre-ordered because of the long lead time for delivery.
Questions:
• Based on the information discussed in fender design and ships characteristics, estimate the size and number of fenders that will be required for budgeting purposes. Basis for selection of vessel characteristics and fender type must be discussed to demonstrate appreciation of the methods - source of information and relevant standards must be referenced. The calculations relating to fender sizing and number of fenders must be clearly set out. Any issues which will need to be taken into consideration for detailed design of the whole fender system by the fender specialist should be noted.
Harbour Geometry
The site for a proposed container port is sheltered from wind and swell waves, but experiences long period infragravity waves with a peak period of 90 s.
• For each of the harbour basins shown below calculate the harbour resonance period. Depth is 12m for all basins.
• Which of the basin layouts is least likely to have problems with long period waves? Why? Which is most likely? Why?
Harmonic analysis of tidal measurements at a port site and has quantified the principal tidal constituents for the site:
|
Constituent
|
Amplitude
|
Period
|
Phaselag
|
|
|
R(m)
|
(hours)
|
Speed,ω (radians/hour)
|
Φ(radians) At midnight 0:00 on 1Jan 2010
|
|
M2
|
1.68
|
12.42
|
0.506
|
-1.51
|
|
S2
|
1.02
|
12
|
0.524
|
0.22
|
|
K1
|
0.24
|
23.93
|
0.263
|
0.01
|
|
O1
|
0.15
|
25.82
|
0.243
|
3.09
|
• Predict the tide height, relative to mean sea level, every hour for the month of January 2010 and present as a time series plot. Hint: In a spread sheet, use the formula: to predict the hourly height.
• What are the times and heights of high and low tide on the 27th Jan 2010, to the nearest hour? Is this spring or neap tide?
• Using formula given in the lecture notes, estimate the tidal range? Would you characterise the tide as diurnal or semi-diurnal?