Nuts and Bolts 31/10/13

Haven't done much Physics the last 2 months or so, been too busy with a Marine Engineering course I'm doing at the Hunter Institute - TAFE at Newcastle, this is towards getting my next Chief Engineer's licence. Some random photos below of the marine engineering workshop, Newcastle and the maritime action on the busy harbour (click for bigger versions). Impressive fleet of tugboats they have there. The wineyards up the Hunter Valley are also worth a visit.

 

 

                  

 

Nuts and Bolts

Hi everyone,

There's a very interesting ABC radio interview available online titled The future of Interstellar Travel worth a listen. Various issues are talked about including getting Helium-3 for future fusion reactors and the challenges involved for interstellar travel.

Interesting post on Centauri Dreams regarding Icarus Interstellar. Impressive list of projects they got going. Myself I think it is 100 years too early to start designing starships in 2013 especially since we currently don't have a working industry grade fusion power plant let alone a flight ready version to put on a starship. However the two projects they have listed ie Project Bifrost and X-Physics Propulsion & Power Project  are worth pursuing now. I stopped looking at warp drives and wormholes last year. Although the field equations in General Relativity do have solutions that allow these spacetime curvatures, GR doesn't take into account the properties of the quantum vacuum and isn't a unified model of Physics. The solutions are not realistic in nature and are purely interesting exercises in GR. As for extracting energy out of the quantum vacuum, there are currently no mechanisms to do this.

Another interesting SBS article: Space: the mining frontier. Seems like space mining is making more headlines these days. Interesting issues raised include who owns the Moon, Mars, Asteroids etc and their minerals? Free for all who can afford to develop the space mining infrastructure? No doubt the UN needs to start developing some kind of legal framework as the private space sector is catching on. I wouldn't hold your breath though, one should remember that the International Space Station cost $150bn to build and this is in low earth orbit.

CI. 

Nuts and bolts

It has been an interesting start of the year for 2011 with some recent items worth mentioning:

Marc Millis of the Tau Zero Foundation posted two papers related to interstellar flight:

Progress in revolutionary Propulsion Physics: summarises the current state of where we stand towards a solution? for "timely interstellar flight - to reach other habitable worlds within a human lifespan". There are currently many options available to reach other stars using known physics. Most would take many decades just to reach our neighbour stars and none of them can get us to destinations beyond many light-years away in a timely, human lifespan timeframe. The paper uses many references from the first recent textbook devoted to this area of research and is worth every dollar: Frontiers of Propulsion Science. I like Figure 1 in the paper which graphically shows the many areas of Physics and concepts that need further research grouped by the key barriers to practical interstellar flight as stated in the paper: Non-propellant propulsion, faster than light travel and energy breakthroughs.

Second paper by Marc: Energy, incessant obsolescence, and the first interstellar missions: there's a review here. Regarding the "incessant obsolescence postulate: No matter when an interstellar probe is launched, a subsequent probe will reach the destination sooner and with more modern equipment": better launch as soon as one has the capabilities to do so because the opportunity may not present itself again due to unforseen circumstances in the future or "societal retardation" ie unforseen catastrophies or less energy production. The implicit motivations for interstellar flight, Table 6 in the paper is interesting, apart from the obvious scientific benefits from the mission and safeguarding humanity's long term survival, I liked another reason that Marc mentions in his talk to pursue interstellar flight: it gives nations something to conquer peacefully and together rather than concentrating on conquering each other on Earth.

Significant results released by the Kepler space telescope shows possible candidates for other Earth like planets. From the NASA press release:

"The fact that we’ve found so many planet candidates in such a tiny fraction of the sky suggests there are countless planets orbiting stars like our sun in our galaxy," said Borucki. "Kepler can find only a small fraction of the planets around the stars it looks at because the orbits aren’t aligned properly. If you account for those two factors, our results indicate there must be millions of planets orbiting the stars that surround our sun."

Also checkout APOD, Centauri Dreams, this and this.

Got in the mail a few days ago: Advanced Propulsion Systems and Technologies, Today to 2020. Another major problem to practical interstellar flight is getting the expected large amounts of hardware out of Earth's gravity well into orbit without using chemical rockets. Space elevators have been proposed (which seems only viable if ultra high strength carbon nanotube cables can be commercially fabricated in the required lengths). A more elegant solution? from Space Drive Physics is worth looking into (see Marc's first paper for an introduction, Chapter 3 Prerequisites for Space Drive Science and Chapter 12 Thrusting against the Quantum Vacuum in Frontiers of Propulsion Science). Anyway should be an interesting read.

CI.

Fremantle Harbour, Western Australia.

Dampier Harbour, Western Australia.

A day out on a 100 tonnes mobile slewing crane

I recently finished a course at Botany Cranes to get a WorkCover 100 tonnes mobile slewing crane licence (for work reasons on boats). Because I was the only one in the class, they sent me with one of the crane drivers for a day for a dual lift job to see first hand the operations of the crane and get some dogging experience. I thoroughly enjoyed the course and more importantly passed the big test at the end. The crane I went on was a Liebherr 100 tonnes crane who make some of the best cranes in the world. The other crane that came with us was the 130t crane. A support truck and crew is also needed for the cranes to carry additional hook blocks, counterweights, packing for the outriggers etc.

Leaving the yard from Botany Bay our destination was the P&O container depot near Bankstown to put together an Omega Megastacker crane (brand new) which is used to lift and move shipping containers.



The Cranes



The job

After a toolbox meeting with the other crew, the cranes are parked into position and outriggers for the cranes extended to maintain stability of the crane during lift. Timber packings are used under the outrigger pads to spread the weight of the crane over a larger surface area onto the ground. All the wheels of the crane must be above ground and the crane dead horizontal. There is an electronic equivalent of a spirit level which makes this process fairly straightforward.



Setting up the outriggers



The crane operator will decide what hook blocks are required for the job, what hook radius he will be operating (and hence how much boom needs to be blown out) and more importantly how much the load mass with all lifting gear such as spreader beams need to be included. The crane operator reads the Load Chart for the crane which gives all this important information and will decide how much counterweight needs to be placed at the rear of the crane. All these factors will dictate what the maximum load the crane can lift for those parameters. With the boom fully extended, this crane would tip over if the operator forgets to place counterweights on the crane. The Liebherr cranes have an onboard computer which also makes all this process straightforward and safe (we don't want the crane to be tipping over or brake the $2.5 mil crane!). The more the boom is blown out or the more the boom is lowered for a given boom length, the less the crane can lift.

After unhooking the hook block at the front of the crane and setting up the counterweights, the crane operator blows out the necessary boom sections. Everything is hydraulically operated and one selects from the computer screen how much boom we want. Two heavy hauler trucks turned up with the Megastacker's boom and arms, nice $20000 paintwork!



The first truck looks like a Transformer in disguise? ;-)



After both cranes are setup and the truck with the first part of the Megastacker in position, the dogmen setup the chain slings required for the job. One person will direct the crane operators for the dual lift job. This is a delicate operation and both cranes need to work together so no extra stress is placed on the cranes and lifting gear. The first part of the job required the boom section of the Megastacker to be placed into position so the Omega technicians could pop in the holding pins for the boom. Once this was done hydraulic rams needed to be lifted and bolted on both sides. The position of the boom had to be in perfect alignment otherwise the pins wouldn't go in.



Putting the million dollar Megastacker together



After the boom section and rams were secured, the next part of the job was to lift and attach the grabber (which grabs and locks into the containers). This was also a delicate operation. Hydraulic rams needed also to be lifted and bolted into position.

The grabber section for the Megastacker

By late afternoon the job was finished and it was time to pack up the gear and stow the cranes for road travel. Because of the tare weight of these cranes, they aren't allowed to travel on some bridges (including Sydney Harbour bridge), tunnels etc so he needs to have a good read of a street directory to decide what is the best route to get to and from a job. We make it back to the Botany Cranes yard after heavy traffic on the main roads. With all the construction that goes around the city, the other cranes are also out doing jobs.

So there you go, great day out and learnt a lot. If you want to see how big these cranes get, checkout the Liebherr 1200 tonnes mobile slewing crane! (Other crane types get even bigger). Doing the Dogman course at the moment (at another school because of timetable reasons). A Dogman is the person who slings the loads, directs the crane operator etc, big test in a few days so better get back to studying! Till next time.

CI.

Nuts and bolts (15/12/09)

Some interesting items I came across recently worth a look at:

Interstellar Propulsion Research: Realistic Possibilities and Idealistic Dreams by Les Johnson gives an introductory rundown on the current status of possible interstellar missions and propulsion options. Apart from the mentioned warp drive (update: read this and this), all of the options are based on sound physics however all of them have severe technical and engineering difficulties to overcome if they are going to happen one day. Ironically getting the hardware required into orbit for these big spacecraft could be the biggest hurdle to overcome as using chemical rockets is expensive. The above options are based on our current understanding of Physics and we still have a lot to learn how nature really works.

The Final Frontier: The Science of Star Trek, interview with Lawrence Krauss. I read the first version of his book years ago and found it quite stimulating reading should interest all you Star Trek fans out there. I saw the world premiere opening of the movie at the Sydney Opera House and got a few autographs myself from the (new) Spock, Sulu and JJ Abrams,  I liked the movie.

A Blueprint for a Quantum Propulsion Machine, here's also a review from Paul Gilster on this paper by Alexander Feigel. It remains to be seen if these so called "magneto-electric particles" do change the momentum of the quantum vacuum and thereby provide a means to change the orientation of a spacecraft without using propellant although many do this already using gyroscopes for eg however the physics if sound would be very interesting as this would provide another avenue to study the Quantum Vacuum. Another paper on this worth reading is here.

Been busy working on Sydney Harbour most days day and night as it is the busy season here. Some recent photos: Nice sailing boat in Farm Cove and checkout this sailing boat skipper going under the Anzac bridge, got his air draft right! Big tow job Bradley's Head outbound (click on photos for larger version).