Battle: Dar es Salaam vs Nairobi

Battle: Dar es Salaam vs Nairobi

Mji wote ndio huo.....some storeys na changudoa swath of uswazi hovels
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Yosef Festo said:
Hapo mtapona(Diesel - electric train iko sawa), hapa ndakubaliana na wewe.

soma hii report kuhusu electrification of freight trains

Electrifying freight trains in the U.S. is a really bad idea
[Only passenger rail ought to be electrified, though since buses are far more energy efficient, this is arguable ( Why is passenger rail so damned inefficient , What is most energy efficient mass transit mode: bus, rail, or auto? , and Challenges facing California’s high-speed rail).
Alice Friedemann www.energyskeptic.com author of “ When Trucks Stop Running: Energy and the Future of Transportation ”,
High-speed passenger rail is all the rage, but when it comes to electrification of America’s freight trains there’s almost total silence. Yet Europe and Russia have electrified freight trains, so why not here?
I had to do a lot of research to reach this conclusion, because there are few peer-reviewed, railroad conference, congressional hearings, industry magazines, life cycle analyses, energy returned on invested, government agency, or books and journal articles within the University of California library system on freight electrification in America.
But it soon became clear, that extremely high capital costs, return on investment, and limited grid and generating capacity are the main reasons freight rail hasn’t been electrified in the United States. Electrification is “not currently economical for long-haul freight service” (USDOE).
Return on Investment
In Europe, Russia, China, and other countries, the government paid for electric passenger rail and electric freight trains joined the party.
In America, freight railroads are privately owned companies that rank projects by their return on investment or they’ll go out of business. Since railroads are already spending five times more than the average manufacturing company to maintain and improve what they have with a huge chunk of their earnings, there’s no money or return on investment reasons to electrify. From the railroad company’s point of view, electrification is an extremely expensive, high risk proposition.
Perhaps if oil prices were still as high as their peak price in 2008, railroad companies would consider electrification, but since they can pass on the higher cost of diesel to their customers via fuel surcharges, perhaps not.
The only freight electrification project being considered in the United States is a $28 billion dollar project in the Los Angeles area. It would combine electrified passenger trains with trains specifically designed to handle cargo containers on a fully elevated guideway system from Los Angeles area ports to distribution centers about 30 miles away.
The main argument for freight rail electrification is that it will pay for itself when oil prices rise and electricity prices grow cheaper as renewable power is added to the electric grid. Yet it’s a bold assumption to assume that electricity will fall in price because at this point in time, the energy storage systems needed to store extra wind and solar power and keep the grid stable (Halper) are still not cheap enough, long-lasting enough, or reliable enough (CEC). Nor is it like the grid will be expanded enough to integrate intermittent power (Wald). Currently the grid is stabilized by fast-reacting natural gas power plants, and it’s possible natural gas production will peak in 2016 or 2017 (Hughes, Powers) and we don’t have enough LNG facilities to import natural gas currently.
Capital Costs:
Electrification is WAAAAY too expensive in America
It’s hard to figure out the cost of electrifying America’s freight trains, because most estimates for electrification are for passenger rail, which can be quite expensive — California’s 520 miles of high-speed rail is estimated to cost $68 billion (Nagourney), which is $130.7 million per mile (times 200,000 miles of freight rail = $26 trillion dollars).

Electrification of freight rail system would cost at least a trillion dollars because freight trains need more electricity than passenger trains since they’re much heavier. A coal train often weighs over 20,000 tons, but a passenger train is likely to weigh less than 1,000 tons.

The extra weight of a freight train would require 6 to 24 megawatts (MW) of power (8,000-32,000 Horse Power). This is 4 to 24 times more power than passenger trains need. Light rail can get by on 1 MW or less, a heavy commuter train 3 to 4 MW, and a high-speed intercity train 4 to 6 MW. And passenger trains need only 25kV lines, but you’d want to have at least 50kV for freight trains to minimize the number of substations (Iden 2009).

When you multiply out the power for just one freight train to many trains over long distances, you’d need a huge amount of power. For example, you’d need 1,500 MW to go the 2,000 miles between Chicago to Los Angeles, equal to three large conventional power plants (FRA). So with 160,000 miles of tracks, you’d need the equivalent of 240 power plants. Of course, some of this power already exists, but it’s likely new power plants, over-sized substations, transmission lines, and so on would be need to be built since railway electrification load is one of the most difficult for an electric utility to cope with (Boyd July 2009).

Third rail isn’t an option for freight trains since it’s too dangerous, unable to deliver the high power needed, and easily clogged with leaves and ice.
Some of the costs to electrify include:
$125 to $250 billion to replace 25,000 locomotives with $5 million all-electric locomotives (SCAG 2012) or $10 million dollar ALP-45DP dual-mode locomotives (Pernicka) if not more, since these passenger locomotives aren’t powerful enough to haul freight trains.
$800 billion to electrify 200,000 miles of railroad tracks with overhead wires, which need to be much higher than anywhere else in the world because of America’s highly energy-efficient double stack trains, which carry twice as much cargo per gallon of fuel. The average cost of three passenger rail projects was $3,980,000 : $3.96 million (SCRRA), $4.55 million (Caltrain), $3.42 million (Metrolinx).
Unknown billions to add new power plants, transformers, substations, new infrastructure to unload and load containers now that overhead wires are in the way, raise bridges and tunnels for overhead wires, and so on.
Why Electrify? Diesel-electric locomotives are
already electric and more energy efficient than electric locomotives
Diesel-electric locomotives have their own 40% or higher energy efficient diesel engine power station on board (USDOE) instead of hooking up to an external electric distribution system. This is far less cumbersome and expensive than overhead wires or a third rail (James, Smil), and gives diesel-electric locomotives an overall efficiency of 30%.
Conversely, electric locomotives are getting their electricity from inefficient power plants, with a 35.6% average efficiency, plus another 6% loss over transmission and distribution lines. By the time the energy gets to the train wheels, you’ve lost 75 percent of the energy, giving electric locomotives an overall efficiency of 25%.
Since railroads have spent billions of dollars to replace or renovate diesel-electric locomotives to comply with Tier 4 EPA standards, and 69% of electricity is generated with fossil fuels, its arguable how much “greener” electric locomotives are.
Detailed calculations:
30% efficient Diesel-electric locomotives .
Diesel engine 40% or more efficient (USDOE) * 92% Generator * 98% rectifier * 92% electric motor * 95% transmission * 95% traction auxiliaries (Hoffrichter) = Vehicle efficiency 30%
25% efficient Electric locomotives . 100% electricity at locomotive * 95% feed cable * 95% Transformer * 97.5% Control system/power electronics * 95% electric motors * 95% transmission * 95% traction auxiliaries = Vehicle efficiency 76% (Hoffrichter) * 35.6% overall average energy efficiency of electric power generation plants (EIA 2012) * 94% transmission and distribution losses (EIA 2014 FAQ2) = Vehicle efficiency 25.4%.
6% average energy efficiency of United States power plants: a) percent of electricity generated by: coal (40), natural gas (28.5), oil (.5), nuclear (19), renewable/other (12) (EIA 2014 A8). b) Average efficiency: coal 32.5%, oil 31%, natural gas 42%, nuclear 32.5%, renewable/other 35.9% (EIA 2014 FAQ1, EIA 2012 8.1, EIA 2014 A6).
Electrify with Batteries? Been there, done that. It didn’t work out.
Railroads have been experimenting with electric locomotives since 1838. In America, 126 battery-operated locomotives have been built, 14 of them battery only, the others had gas or diesel engines as well. Not a single one was a long-haul locomotive. They all were local, yard switcher locomotives that assembled and disassembled trains. What all of these experiments revealed is that batteries weigh a lot, break easily, are difficult to maintain, have little usable power, and often have to be replaced, going beyond expected costs. When pushed beyond their safe depth of discharge, or damaged after a hard coupling, the train might stop running, not such a great thing in a switching yard, but definitely not cool for a long-haul locomotive that breaks down in the middle of nowhere (Iden 2014). Energy storage devices are too expensive and incapable of moving a train a reasonable distance (Vitins).
Batteries for regenerative braking. Locomotives have very little room to put regenerative braking batteries, so instead, a battery tender car coupled-and-connected to the real locomotive, or a separate locomotive devoted only to energy storage would need to be built (Iden 2014).
Trains are completely different from cars or trucks and much harder to drive and it’s much harder to capture regenerative braking energy. A mile-long train can be going downhill, uphill, and level at the same time, requiring train engineer to play the two types of braking system used on trains like a concert pianist or the train might derail.
A train going down the steep Cajon pass grade could generate as much as 2,744 kWh per train, which would require 525 tons of lead-acid batteries to store. That’s a lot of deadweight to haul when the train returns uphill to the Cajon pass (Painter).
Much of the time the train isn’t using the brakes because the ground is flat or slightly undulating. Only a small minority of tracks known as “hogbacks” can capture regenerative braking, which are steeper uphill and downhill grades about the length of the train.
Other issues with Electrification
Single point of failure. Many events can stop the flow of electricity, causing severe and expensive congestion on the most trafficked routes, such as landslides, earthquakes, high winds, hurricanes, washouts, heat waves, lightning (Smith), locomotive mechanical or electric failure, wires getting struck by vehicles at road crossings, lack of power due to not enough substations, sabotage, terrorist attacks (NAS), and so on. Electric-only locomotives will be stuck wherever they are and need to be rescued by diesel locomotives (SCAG 2012) creating costly and severe congestion on many heavily traveled routes.
It is possible the electric grid won’t always be powerful enough to meet the high energy demands of freight trains. For example, when there are several trains near each other, peak demand, or the locomotives need a lot of power to go uphill, perhaps 22 MW or more.
Political and institutional hurdles . The SCAG project in Los Angeles will be difficult to implement since it encompasses 6 counties and 197 cities who will want to have a say in the project. Now multiply the complexity of affected local, state, and government agencies by tens of thousands when considering a national-scale project to electrify rail.
Diesel locomotives can’t be beat. Diesel engines keep getting better, last a long time, are rugged enough to handle rough patches of rail, and can be rebuilt. Many locomotive engines achieve the equivalent of one million miles before overhaul, equal to 36,000 megawatt-hours (USDOE).
Electrification makes more sense for passenger trains since electricity is good for high speeds, acceleration, and frequent stops. Freight trains are the opposite – they are slow, rarely stopping, and need power, not acceleration. Above all, speeding up freight trains wastes energy. Since most of what’s being hauled doesn’t spoil, freight doesn’t need to get anywhere fast. There are about 5 derailments a day in North America. Imagine the damage an 80 million pound electric train derailing at 100 mph would cause, plus the added costs of the overhead wires being pulled down (Boyd). High speeds would also wear out tracks out faster, requiring expensive maintenance.
If fuel cells ever work out, they could be added to existing locomotives, and make electrification obsolete.
Europe’s Freight Trains Suck. Why copy them?
In European countries, trains often can’t go to other countries, because there are three types of rail gauges, four different voltages, eleven different ways of hooking to the overhead wires, and half their rail lines aren’t electric (Iden 2009).
U.S. freight trains haul about seven times more freight than in Europe due to interoperability. American rail freight is perhaps the cheapest in the world, costing half as much as in Europe and Japan.
American freight trains carry far more cargo using far less energy in longer, heavier, double-stacked trains.
Europe’s electric rail is 80% passenger trains that have priority over freight, making cargo delivery less reliable, one of many reasons freight trains hauled 60% of all cargo in 1950 but only 8% now. American trains haul 43% of all freight (by ton-miles).
Electrify just the busiest corridors
Okay, you’re saying there’s no choice, the oil and other liquid substitute fossil fuels (coal, natural gas) are running out. But if affordable and energy efficient electricity energy storage isn’t developed, we’ll run out of electricity too. So you could hedge your bets and build locomotives that can burn diesel fuel and run on electricity, which is a good idea for other reasons as well.
Currently the entire North American system, from Mexico to Canada, is an interoperable network. Railroads share their tracks and other infrastructure with each other.
In the nineteenth century, each railroad had a different gauge, which ironically increased the need for horses because they were needed to haul cargo and people across town to get on the next rail line to continue their journey.
Partial electrification would balkanize trains again (Iden 2009). It would be expensive to swap electric and diesel locomotives at every electric and non-electric border. You’d need double the staff to maintain both electric and diesel infrastructure. And it would delay trains long enough to shift some freight to trucks, because swapping locomotives, pressurizing brake systems, and safety inspections would take 3 to 6 hours (SCAG 2012).
That’s why the railroads have insisted the only acceptable solution is dual locomotives that are both electric and diesel. There is no freight dual-locomotive yet (Boyd April 2009), and it might cost even more since only 500 to 1,000 new locomotives are sold a year made by just a few companies, so there’s no economies of scale. The cheapest route would be to modify an existing diesel-electric locomotive to also be able to be electric only. To do this, you’d need to add a 50 kV step-down transformer weighing 20,000 pounds that takes up 480 cubic feet of space, switch gear, and more to a locomotive that’s already at the maximum height, width, and length and weight limit and running out of space due to new equipment added to comply with EPA tier 4 emissions requirements. Oh, and you want regenerative braking too? That’ll take up even more space (Iden 2009).
Unintended consequences
If we electrify our rail and both fossil fuels as well as electricity become too expensive or scarce, the easiest way to add more power generation might be new coal power plants. This is happening in India now, and could push the world into irreversible climate change and doom us all, according to Veerabhadran Ramanathan, director of the Center for Atmospheric Sciences at the Scripps Institution of Oceanography and one of the world’s top climate scientists (Harris).
Showstoppers: Capital costs, Credit, Bureaucracy, Regulation, & Overlapping Jurisdiction obstacles.
References
AAR. 2012. Total Annual Spending. How railroads spend their money. American Association of Railroads.
AB2514. July2014. Energy Storage system Plan. White Paper Analysis. City of Anaheim.
Bhargava, B. 1999. Railway electrification systems and configurations. Power Engineering Society Summer Meeting. IEEE vol 1
Boyd, J. 13 Apr 2009. Challenges Loom for Electric Ideas . www.joc.com
Boyd, J. Jul 1, 2009. CSX Cautious on Electrification. www.joc.com
Caltrain. 2008. Caltrain electrification program. Environmental Assessment. U.S. Department of transportation. page 42
CEC. 2014. AB 2514 – Energy Storage System Procurement Targets from Publicly Owned Utilities. Publicly Owned Utility Reports. California Energy Commission.
Cotey, A. September 2012. Caltrain electrification project ready to roll. Progressive Railroading.
EIA. 2012. 8.1. Average Operating Heat Rate for Selected Energy Sources, 2002 through 2012. U.S. Energy Information Administration.
EIA. 2014 A6. Table A6. Approximate Heat Rates for Electricity, and Heat Content of Electricity. U.S. Energy Information Administration.
EIA 2014 A8. Annual Energy Outlook 2014 A8.
Electricity Supply, Disposition, Prices, and Emissions, total electricity generation by fuel
Total Generation (2013). U.S. Energy Information Administration.
EIA. 2014. FAQ1: What is the efficiency of different types of power plants?. U.S. Energy Information Administration.
EIA. 2014. FAQ2: How much electricity is lost in transmission and distribution in the United States? U.S. Energy Information Administration.
Federal Railroad Administration. Dec 14, 2010. Dark Territory Working Group. Railroad Safety Advisory Committee.
FRA. November 19, 2009. Federal Railroad Administration Comparative Evaluation of Rail and Truck Fuel Efficiency on Competitive Corridors. ICF International for U.S. Department of Transportation.Tukija chini hapa Africa, uchumi zilizoendelea na uwezo hili hawawezi fanya.., hope Tanzania will swallow more than they can chew. We know your power supply, it will run passenger trains very well, but freight! I doubt.

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Europe, Asia/ China and Russia, Japan, Mexico and Brazil, kote wanatumia electric al cargo trains. Sasa kwasababu USA hawajaunganisha UMEME ktk train zao za mizigo, hiyo ndiyo sababu pekee ya kufikiria Electrical trains hazifai kusafirisha mizigo ukilinganisha na diesel?. Kweli wamarekani ni Mungu wenu.

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lwiva said:
Bwaaaahhhhaaaa tunavyo waambia dar kubwa mnafikili mchezo licha ya kukesha humu jf na mapicha yote tunayo tuma amjaweza kuijua dar imekaaje kaaje wakati mm nimeijua Nairobi yote Kwa kupitia picha mnazo post
Tena Dar kuna UPANGA WEST NA UPANGA EAST
hata kinondoni kuna KINONDONI A NA KINONDONI B. wakenya wakija dar kila siku ni kupotea potea tu

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Kupenya hizo uswazi hovels kwa ukweli naweza potea.. ..
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joto la jiwe said:
Europe, Asia/ China and Russia, Japan, Mexico and Brazil, kote wanatumia electric al cargo trains. Sasa kwasababu USA hawajaunganisha UMEME ktk train zao za mizigo, hiyo ndiyo sababu pekee ya kufikiria Electrical trains hazifai kusafirisha mizigo ukilinganisha na diesel?. Kweli wamarekani ni Mungu wenu.

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Alikuwa anajipa relief kuwa treni zao za karne ya 10 zinafanana na za Marekani kisa hazitumii umeme? 🤣 🤣 🤣 🤣 🤣 🤣 dunia simama nishuke!
 
VIKING23 said:
Loli love videos....



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Kariakoo is a district. What you think you posted is a Bazaar, not even 1/6 of the entire size of Kariakoo. Do you notice who's dumb here? Halafu, I don't see anything wrong with people selling things along the road. We are not the first world to have boutiques everywhere. The question is, do you have those boutiques? Au ni uchafu huu
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Walker255 said:
Kariakoo is a district. What you think you posted is a Bazaar, not even 1/6 of the entire size of Kariakoo. Do you notice who's dumb here?
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Tatizo anasumbuliwa na chuki pamoja na wivu, hafahamu kuwa kariakoo pekee ina maghorofa mengi kuliko Nairobi.
 
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