Question: Information:  - The term rolling stock originally referred to any vehicles that move on a railway. It has since expanded to include the wheeled vehicles used by businesses on roadways. It usually includes both powered and unpowered vehicles, for example locomotives, railroad cars, coaches, and wagons.  - Zimbabwe, officially the Republic of Zimbabwe, is a landlocked country located in southern Africa, between the Zambezi and Limpopo Rivers. It is bordered by South Africa to the south, Botswana to the west and southwest, Zambia to the northwest, and Mozambique to the east and northeast. Although it does not border Namibia, less than 200 metres of the Zambezi River separates it from that country. The capital and largest city is Harare. A country of roughly 13 million people, Zimbabwe has 16 official languages, with English, Shona, and Ndebele the most commonly used.  - Namibia, officially the Republic of Namibia (German: ), is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and east. Although it does not border Zimbabwe, a part of less than 200 metres of the Zambezi River (essentially a small bulge in Botswana to achieve a Botswana/Zambia micro-border) separates the two countries. Namibia gained independence from South Africa on 21 March 1990, following the Namibian War of Independence. Its capital and largest city is Windhoek, and it is a member state of the United Nations (UN), the Southern African Development Community (SADC), the African Union (AU), and the Commonwealth of Nations.  - Protekon performs maintenance and development services for the ports , railways and terminals of South Africa 's state - owned transportation giant Transnet . It is similar in function to the company Transnet Rail Engineering , which performs mainenance and development for the rolling stock of Transnet 's railways divisions .  - The Bantu languages, technically the Narrow Bantu languages (as opposed to "Wide Bantu", a loosely defined categorization which includes other Bantoid languages), constitute a traditional branch of the NigerCongo languages. There are about 250 Bantu languages by the criterion of mutual intelligibility, though the distinction between language and dialect is often unclear, and "Ethnologue" counts 535 languages. Bantu languages are spoken largely east and south of present-day Cameroon, that is, in the regions commonly known as Central Africa, Southeast Africa, and Southern Africa. Parts of the Bantu area include languages from other language families (see map).  - Africa is the world's second-largest and second-most-populous continent. At about 30.3 million km² (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area and 20.4 % of its total land area. With 1.1 billion people as of 2013, it accounts for about 15% of the world's human population. The continent is surrounded by the Mediterranean Sea to the north, both the Suez Canal and the Red Sea along the Sinai Peninsula to the northeast, the Indian Ocean to the southeast, and the Atlantic Ocean to the west. The continent includes Madagascar and various archipelagos. It contains 54 fully recognized sovereign states (countries), nine territories and two "de facto" independent states with limited or no recognition.  - Transnet Rail Engineering, formerly known as Transwerk, is a subsidiary of Transnet whose business it is to keep South Africa's trains rolling. According to the Operational Report at Transnet, Transnet Rail Engineering's responsibility includes "the maintenance, upgrade and manufacture of locomotives, wagons, coaches, rolling stock components and associated transport equipment". The company operates seven factories in South Africa. Transnet Rail Engineering maintains sales offices in 7 European countries, 11 African countries and in Australia.  - The Carlton Centre is a skyscraper and shopping centre located in downtown Johannesburg, South Africa. At , it has been the tallest office building in Africa since 1973. The Carlton Centre has 50 floors. The foundations of the two buildings in the complex are in diameter and extend down to the bedrock, below street level. The building houses both offices and shops, and has over 46 per cent of the floor area below ground level. The Carlton Centre is linked to the Carlton Hotel by a below-ground shopping centre with over 180 shops.  - Sub-Saharan Africa is, geographically, the area of the continent of Africa that lies south of the Sahara desert. According to the UN, it consists of all African countries that are fully or partially located south of the Sahara. It contrasts with North Africa, whose territories are part of the League of Arab states within the Arab world. Somalia, Djibouti, Comoros and Mauritania are geographically in Sub-Saharan Africa, but are likewise Arab states and part of the Arab world.  - Australia, officially the Commonwealth of Australia, is a country comprising the mainland of the Australian continent, the island of Tasmania and numerous smaller islands. It is the world's sixth-largest country by total area. The neighbouring countries are Papua New Guinea, Indonesia and East Timor to the north; the Solomon Islands and Vanuatu to the north-east; and New Zealand to the south-east. Australia's capital is Canberra, and its largest urban area is Sydney.  - South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded on the south by of coastline of Southern Africa stretching along the South Atlantic and Indian Oceans, on the north by the neighbouring countries of Namibia, Botswana and Zimbabwe, and on the east and northeast by Mozambique and Swaziland, and surrounding the kingdom of Lesotho. South Africa is the 25th-largest country in the world by land area, and with close to 56 million people, is the world's 24th-most populous nation. It is the southernmost country on the mainland of the Old World or the Eastern Hemisphere. It is the only country that borders both the Atlantic Ocean and the Indian Ocean. About 80 percent of South Africans are of Sub-Saharan African ancestry, divided among a variety of ethnic groups speaking different Bantu languages, nine of which have official status. The remaining population consists of Africa's largest communities of European (white), Asian (Indian), and multiracial (coloured) ancestry.  - Johannesburg (also known as Jozi, Joburg and eGoli) is the largest city in South Africa and is one of the 50 largest urban areas in the world. It is the provincial capital of Gauteng, which is the wealthiest province in South Africa. While Johannesburg is not one of South Africa's three capital cities, it is the seat of the Constitutional Court. The city is located in the mineral-rich Witwatersrand range of hills and is the centre of large-scale gold and diamond trade.  - The Indian Ocean is the third largest of the world's oceanic divisions, covering (approximately 20% of the water on the Earth's surface). It is bounded by Asia on the north, on the west by Africa, on the east by Australia, and on the south by the Southern Ocean or, depending on definition, by Antarctica. It is named after the country of India. The Indian Ocean is known as "Ratnkara", ""the mine of gems"" in ancient Sanskrit literature, and as "Hind Mahsgar", ""the great Indian sea"", in Hindi.  - Transnet SOC Ltd is a large South African rail, port and pipeline company, headquartered in the Carlton Centre in Johannesburg. It was formed as a limited company on 1 April 1990. A majority of the company's stock is owned by the Department of Public Enterprises, or DPE, of the South African government. The company was formed by restructuring into business units the operations of South African Railways and Harbours and other existing operations and products.  - Lesotho, officially the Kingdom of Lesotho, is an enclaved, landlocked country in southern Africa completely surrounded by South Africa. It is just over in size and has a population slightly over two million. Its capital and largest city is Maseru.   - A locomotive or engine is a rail transport vehicle that provides the motive power for a train. The word originates from the Latin "loco"  "from a place", ablative of "locus", "place" + Medieval Latin "motivus", "causing motion", and is a shortened form of the term "locomotive engine", first used in the early 19th century to distinguish between mobile and stationary steam engines.  - Southern Africa is the southernmost region of the African continent, variably defined by geography or geopolitics, and including several countries. The term "southern Africa" or "Southern Africa", generally includes Angola, Botswana, Lesotho, Malawi, Mozambique, Namibia, South Africa, Swaziland, Zambia, and Zimbabwe. From a political perspective the region is said to be unipolar with South Africa as a first regional power.  - The Old World consists of Africa, Europe, and Asia, regarded collectively as the part of the world known to Europeans before contact with the Americas. It is used in the context of, and contrast with, the New World (Americas).  - Europe is a continent that comprises the westernmost part of Eurasia. Europe is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, and the Mediterranean Sea to the south. To the east and southeast, Europe is generally considered as separated from Asia by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways of the Turkish Straits. Yet the non-oceanic borders of Europea concept dating back to classical antiquityare arbitrary. The primarily physiographic term "continent" as applied to Europe also incorporates cultural and political elements whose discontinuities are not always reflected by the continent's current overland boundaries.  - Swaziland, officially the Kingdom of Swaziland (or ; Swazi: "Umbuso weSwatini"; sometimes called kaNgwane or Eswatini), is a sovereign state in Southern Africa. It is neighboured by Mozambique to its northeast and by South Africa to its north, west and south. The country and its people take their names from Mswati II, the 19th-century king under whose rule Swazi territory was expanded and unified.  - The Eastern Hemisphere is a geographical term for the half of the earth that is east of the prime meridian (which crosses Greenwich, England) and west of the antimeridian. It is also used to refer to Europe, Asia, Africa, and Australia, in contrast with the Western Hemisphere, which includes North and South America. This hemisphere may also be called the "Oriental Hemisphere". In addition, it may be used in a cultural or geopolitical sense as a synonym for the "Old World".  - A vehicle (from ) is a mobile machine that transports people or cargo. Typical vehicles include wagons, bicycles, motor vehicles (motorcycles, cars, trucks, buses), railed vehicles (trains, trams), watercraft (ships, boats), aircraft and spacecraft.  - Botswana , officially the Republic of Botswana, is a landlocked country located in Southern Africa. The citizens refer to themselves as "Batswana" (singular: "Motswana"). Formerly the British protectorate of Bechuanaland, Botswana adopted its new name after becoming independent within the Commonwealth on 30 September 1966. Since then, it has maintained a strong tradition of stable representative democracy, with a consistent record of uninterrupted democratic elections.  - Mozambique (or ), officially the Republic of Mozambique (or "") is a country in Southeast Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west, and Swaziland and South Africa to the southwest. It is separated from Madagascar by the Mozambique Channel to the east. The capital and largest city is Maputo (known as "Lourenço Marques" before independence).    What entity does 'protekon' has the relation 'headquarters location' with?
Answer:
johannesburg