Marine engineering students Ika Suwandi, left, Deny Suriyono and
Yuda Apri explain the dynamics of their braking system, which uses
waterjets to slow ships. (JG Photo/Amir Tejo)
Marine engineering students Ika Suwandi, left, Deny Suriyono and Yuda Apri
explain the dynamics of their braking system, which uses water jets to
slow ships. (JG Photo/Amir‚Tejo)
Young Inventors Put Brakes on Ship Collisions
Ever wondered how ships slow down?
Judging from the high number of shipping collisions, whatever braking
system vessels are currently using seems to be somewhat ineffective.
That is what's been exercising the minds of three students from the
Surabaya Institute of Technology (ITS).
Ika Suwandi, from the school of marine engineering department, Deny
Suriyono, from the naval architecture department, and Yuda Apri, from the
ship engineering department, became interested in the problem when they
saw that 55 of the 208 marine accidents between 2004 and 2008 were
collisions.
And was this at a time when navigation equipment is becoming more
sophisticated.
Perhaps the ships brake system was not working effectively,Ika said.
The three studied the conventional brake system with an eye to uncovering
its weaknesses. It is based on a reversal of a ship's propellers.
This system showed several weaknesses. It could not bring ships to a
sudden halt because of the time and distance required to reverse the
propellers, which depended on their size. And the propellers were prone to
break if suddenly thrust into reverse.
After months of studies and experiments under the tutelage of lecturer
Hasan Ikhwani, the students came up with a ship brake based on propulsion
from water jets.
They used the very system employed to move superfast ships to brake ships
effectively.
Water is drawn from under the boat into a pump-jet on the boat and then
expelled through a nozzle.
The system was first developed to propel boats in the 1950s in New Zealand.
“With the use of water jet propulsion, ships can be halted more
effectively,Ika said.
To maximize its effectiveness, the system was installed in the bow, or the
front, of the ship.
Following laboratory testing and field tests, a ratio of 1:2 was reached
for the strength of the water jet necessary to halt a ship effectively.
Under such ratio, a ship travelling at 20 nautical knots would need jets
that would be able to move the ship at half that speed.
Ika said tests had shown that if the ratio was changed, with a higher jet
speed, the brake system would become ineffective because the stern would
lift up as the boat got projected in the opposite direction, and the boat
could also reverse too much.
The head of the National Ship Design and Engineering Center, Aires
Sulisetyono, took his hat off at the students creativity. This could
become a solution to an important problem in the shipping world,Aries
said.
John Sihombing, the general manager of the Surabaya branch of the state
shipping line PT Pelni, said it might be able to lower the number of naval
incidents.
It should be shared with shipping associations,he said.
--
http://www.its.ac.id
Yuda Apri explain the dynamics of their braking system, which uses
waterjets to slow ships. (JG Photo/Amir Tejo)
Marine engineering students Ika Suwandi, left, Deny Suriyono and Yuda Apri
explain the dynamics of their braking system, which uses water jets to
slow ships. (JG Photo/Amir‚Tejo)
Young Inventors Put Brakes on Ship Collisions
Ever wondered how ships slow down?
Judging from the high number of shipping collisions, whatever braking
system vessels are currently using seems to be somewhat ineffective.
That is what's been exercising the minds of three students from the
Surabaya Institute of Technology (ITS).
Ika Suwandi, from the school of marine engineering department, Deny
Suriyono, from the naval architecture department, and Yuda Apri, from the
ship engineering department, became interested in the problem when they
saw that 55 of the 208 marine accidents between 2004 and 2008 were
collisions.
And was this at a time when navigation equipment is becoming more
sophisticated.
Perhaps the ships brake system was not working effectively,Ika said.
The three studied the conventional brake system with an eye to uncovering
its weaknesses. It is based on a reversal of a ship's propellers.
This system showed several weaknesses. It could not bring ships to a
sudden halt because of the time and distance required to reverse the
propellers, which depended on their size. And the propellers were prone to
break if suddenly thrust into reverse.
After months of studies and experiments under the tutelage of lecturer
Hasan Ikhwani, the students came up with a ship brake based on propulsion
from water jets.
They used the very system employed to move superfast ships to brake ships
effectively.
Water is drawn from under the boat into a pump-jet on the boat and then
expelled through a nozzle.
The system was first developed to propel boats in the 1950s in New Zealand.
“With the use of water jet propulsion, ships can be halted more
effectively,Ika said.
To maximize its effectiveness, the system was installed in the bow, or the
front, of the ship.
Following laboratory testing and field tests, a ratio of 1:2 was reached
for the strength of the water jet necessary to halt a ship effectively.
Under such ratio, a ship travelling at 20 nautical knots would need jets
that would be able to move the ship at half that speed.
Ika said tests had shown that if the ratio was changed, with a higher jet
speed, the brake system would become ineffective because the stern would
lift up as the boat got projected in the opposite direction, and the boat
could also reverse too much.
The head of the National Ship Design and Engineering Center, Aires
Sulisetyono, took his hat off at the students creativity. This could
become a solution to an important problem in the shipping world,Aries
said.
John Sihombing, the general manager of the Surabaya branch of the state
shipping line PT Pelni, said it might be able to lower the number of naval
incidents.
It should be shared with shipping associations,he said.
--
http://www.its.ac.id
