With GPS systems and other geographical technology being as sophisticated as it now is, do lighthouses still serve an integral purpose? Are they more now just in case the captain/crew lapses on the monitoring of navigation systems? Obviously lighthouses are more immediate and I guess tangible, but do they still fulfil a purpose beyond mitigating basic human error?
In: 5120
Tuesday a ferry ran aground in the Philippines.
February 17 cargo ship ran aground in the Black Sea.
February 4 cargo ship ran aground in Indonesia.
Even with the technology stuff happens and extra methods of preventing bad things happening in hazardous places is a decent investment.
The US Coast Guard has decommissioned a lot of lighthouses but not all because some are in places where there is sufficient traffic and enough of a hazard to warrant keeping them active
Tuesday a ferry ran aground in the Philippines.
February 17 cargo ship ran aground in the Black Sea.
February 4 cargo ship ran aground in Indonesia.
Even with the technology stuff happens and extra methods of preventing bad things happening in hazardous places is a decent investment.
The US Coast Guard has decommissioned a lot of lighthouses but not all because some are in places where there is sufficient traffic and enough of a hazard to warrant keeping them active
Defense in depth.
Just imagine that it’s cloudy and stormy, and you’re racing to get to safe berth, and your gps and radio navigation go out. Sure it doesn’t happen often. But it could happen.
You *think* you know where you are. You’re pretty confident. But you know that if you’re wrong you could end up broken up on rocks and lost in the storm. Everything is pitch black, still no instruments, nothing to go by except dead reckoning and maybe your compass…
… and then a flash hits you. From the lighthouse. From the beam size and the location you can now figure pretty accurately where you are, adjust course, and avoid certain death on the rocks that were just out of sight.
Still seem unneccessary?
Defense in depth.
Just imagine that it’s cloudy and stormy, and you’re racing to get to safe berth, and your gps and radio navigation go out. Sure it doesn’t happen often. But it could happen.
You *think* you know where you are. You’re pretty confident. But you know that if you’re wrong you could end up broken up on rocks and lost in the storm. Everything is pitch black, still no instruments, nothing to go by except dead reckoning and maybe your compass…
… and then a flash hits you. From the lighthouse. From the beam size and the location you can now figure pretty accurately where you are, adjust course, and avoid certain death on the rocks that were just out of sight.
Still seem unneccessary?
Ok, this is one I can answer. When you are navigating a ship, the more methods you have of fixing your position the better.
With modern GPS and electronic chart systems, there are rarely huge faults, but as you may have an oil tanker with 22 men on board and 150,000 tonnes of crude oil, a rare fault could lead to absolute disaster.
So, when driving a ship, you also use other methods which could be:
A) Celestial navigation — using the stars/planets to work out where you are – only accurate enough for deep sea work really. The best celestial fix I ever got at sea matched the GPS by around a tenth of a mile, but that was with practicing almost every day for weeks.
B) Compass directions (bearings) — take the direction (bearing) of three objects at the same time using the ship’s comapss, then draw the lines on the chart, and where they all cross (if you got a good fix) that’s where you are.
C) Soundings (depth of water) — really only good for knowing your progress along a line if you know the depths.
D) Radar — either you can use the same method as b, but use radar bearing, or you just match the lad on your radar screen to the chart.
There are some others, but mainly you use GPS, and B and D as back ups. Which now means if you want to take a visual bearing of something at night, you need it to have a light. So basically a lighthouse gives a very defined and identifiable point from which to take a compass bearing.
As an aside, every light house in a certain section of shore will have a different rhythm and tempo, which the chart will tell you, so that you know which light house you are looking at. Some will also have light sectors, which will show different colours depending on the direction you are looking at them.
There are some more complex uses, but I’ll keep it as that for an (admittedly complex) ELI5 answer.
“The GPS says land is .25 km away.”
“Oh, there’s the lighthouse. Keep away from those rocks.”
Human brains don’t translate numbers into reality on a very intuitive level. For short-range navigation, you really need to see what you’re doing.
“The GPS says land is .25 km away.”
“Oh, there’s the lighthouse. Keep away from those rocks.”
Human brains don’t translate numbers into reality on a very intuitive level. For short-range navigation, you really need to see what you’re doing.
Redundancy is the big reason.
Why do we even have windows on ships if we can just stare at a GPS? Visual is a great indicator to get your bearing.
Remember that GPS only figures out your position and movement over ground. In maritime navigation we do need to know where the bow is pointing, which might be a completely different direction when we are affected by currents and wind.
In my neck of the woods we do have a foreign power that likes to jam GPS/GLONASS/GALILEO every so often, so I would not be casting away without the skills and means to navigate without satellites.
Redundancy is the big reason.
Why do we even have windows on ships if we can just stare at a GPS? Visual is a great indicator to get your bearing.
Remember that GPS only figures out your position and movement over ground. In maritime navigation we do need to know where the bow is pointing, which might be a completely different direction when we are affected by currents and wind.
In my neck of the woods we do have a foreign power that likes to jam GPS/GLONASS/GALILEO every so often, so I would not be casting away without the skills and means to navigate without satellites.
Ok, this is one I can answer. When you are navigating a ship, the more methods you have of fixing your position the better.
With modern GPS and electronic chart systems, there are rarely huge faults, but as you may have an oil tanker with 22 men on board and 150,000 tonnes of crude oil, a rare fault could lead to absolute disaster.
So, when driving a ship, you also use other methods which could be:
A) Celestial navigation — using the stars/planets to work out where you are – only accurate enough for deep sea work really. The best celestial fix I ever got at sea matched the GPS by around a tenth of a mile, but that was with practicing almost every day for weeks.
B) Compass directions (bearings) — take the direction (bearing) of three objects at the same time using the ship’s comapss, then draw the lines on the chart, and where they all cross (if you got a good fix) that’s where you are.
C) Soundings (depth of water) — really only good for knowing your progress along a line if you know the depths.
D) Radar — either you can use the same method as b, but use radar bearing, or you just match the lad on your radar screen to the chart.
There are some others, but mainly you use GPS, and B and D as back ups. Which now means if you want to take a visual bearing of something at night, you need it to have a light. So basically a lighthouse gives a very defined and identifiable point from which to take a compass bearing.
As an aside, every light house in a certain section of shore will have a different rhythm and tempo, which the chart will tell you, so that you know which light house you are looking at. Some will also have light sectors, which will show different colours depending on the direction you are looking at them.
There are some more complex uses, but I’ll keep it as that for an (admittedly complex) ELI5 answer.
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