LIGHT RAIL VEHICLE DESIGN CHARACTERISTICS - LRV Bumpers

A key feature of many modern LRVs is a front end bumper that is designed around crash energy management principles. The bumper typically extends from a few inches above the rails to the floor level of the LRV. The bumper is designed to rotate upward, revealing the LRV coupler. The coupler itself, which traditionally extended out an appreciable distance beyond the front of the LRV, is now hinged and can be folded back behind the closed bumper. The bumper conceals the traditional anticlimber as well as the coupler, but is not primarily intended to be merely cosmetic.

Because of the crash energy management (CEM) design, in the event of a collision, the bumper actually minimizes damage to any motor vehicles. It also makes it far less likely that an automobile would become wedged beneath the front of an LRV. Similarly, the bumper makes it more likely that a struck pedestrian will be pushed aside instead of being pulled beneath the front of the LRV. As of 2011, bumpers are not universal on new light rail vehicles, but it seems likely that they will become a common feature for any LRVs that have extensive operations in public streets.

THE FIRST CASE OF MONOTHEISM (2 of 2)

Aton/Aten belief system has banned everything connected to myths, magic, and witchcraft. 'All the formulas, and gadgets related to magic were burned. Jinns, satans, monsters, spirits, demi-gods, demons, even Osiris was burned to ashes.' Akh-en-aton accepted the energy of the sunlight as the source of life on earth, and worshipped this energy as a symbol of his god's power. He boasted his happiness caused by the 'creation', and his Ma'at (honest and just) life. Despite all the richness and extravagance that could be seen in the art of the Amarna period there was no other representation or a personal image of the Sun-God Aten/Aton. Because Akh-en-aton did not allow the making of the idols or images of the Sun-God. The king said that the real god has no form, and kept his position until the end of his life. A last point: There was an absolute silence about Osiris and the kingdom of the dead.

Despite the fact that Akh-en-aton has banned all the other gods and insisted on his Sun-god as the sole god to be worshipped, (in other words he was really a monotheist), he was accused first with anti-theism then with atheism. Egyptian pharaoh Akh-en-aton is the first registered atheist in the history of mankind. Although Akh-en-aton has worshipped the sole god, the Sun-god Aten/Aton, he was accused by his son in law Tut-ankh-aton- who replaced him - with atheism, because he has rejected the official gods. Tut-ankh-aton's name was changed to Tut-ankh-amen as the belief system of Aton was abandoned following the death of Akh-en-aton. Here is a hymn which expresses the basics of the Aton/Aten cult:

• "..How manifold it is, what you have made!...
• O sole god, like whom there is no other!
• You created the world according to your desire,
• While you were alone;
• All men, cattle and wild beasts,
• Whatever is on earth, going on its feet,
• And whatever is on high flying with its wings
• The countries of Syria and Nubia, the land of Egypt,
• You settled every man in his place,
• You supplied their necessities,
• Everyone has his food, and his time of life is reckoned.
• Their tongues are separate in speech,
• And their natures as well;
• Their Skins are distinguished,
• As you distinguished the foreign peoples...
• ...there is none other that knows you,
• Save your son Nefer-kheperu-Re Wa-en-Re,
• For you have made him well versed in your plans and in your strength."

(Believers of believes system today may find some of the exact attributes of their god in this hymn). But, Aten cult/belief system did not enjoy popularity, and most probably was limited to the close circle around the pharaoh. A period of anarchy followed until the year 1350 B.C. when general Haremhab/Horemheb reestablished the order. In this interim period the old belief systems were reintroduced, and Aten belief system was abandoned. Akh-en-aton's capital city was demolished and looted and Akh-en-aton was treated like an ordinary criminal, omitted from the king lists, and became 'that criminal Akh-en-aton.'

Since Akh-en-aton all those who have rejected or opposed the official gods in Egypt, Greece or Rome were accused of atheism. Socrates, Anaxagoras, Diagoras, Protagoras and others thinking like them were amongst those who were accused of atheism. The idea of monotheism which had risen with Akh-en-aton had to stay in darkness for a long time. Some scholars find the origin of the sole god, the father god of the codebooks of today believes system, in Egypt, in the Aton belief system. Some western historians maintain that next believes system had got the idea of the sole god from Akh-en-aton.

LIGHT RAIL VEHICLE DESIGN CHARACTERISTICS - Carbody Strength, Crashworthiness, and Mass

Up until about 1970, there were no codes or standards for the overall strength requirements of a transit vehicle carbody that were fully based in engineering principles. Beginning about that time, the usual requirement in specifications became that the carbody needed to accept, without structural failure, a longitudinal static “buff load” equal to two times its own mass.

This was known as the “2-g standard,” although it was never actually codified as a mandatory requirement except in the State of California.[5] Under the 2-g standard, if the vehicle weighed 125,000 pounds [556 kilonewtons] it needed to have a minimum buff strength of 250,000 pounds [1,112 kilonewtons].

Naturally, the addition of more steel to make the carbody stronger also increased its mass, with the result that new transit cars were much heavier than their predecessors. This extra weight had impacts on power consumption, structure design, and track design.

THE FIRST CASE OF MONOTHEISM (1 of 2)

At the end of the 18th dynasty Egypt becomes a world power. The developments in religious thinking of the administrators and intellectual top class reflects this new imperialism, the by-product of which is the monotheism. God is a reflection of the pharaoh who is the absolute ruler of a great world empire. The idea of a universal god appears with the influence of the priests of the Sun-god in On (Heliopolis) who may have become more powerful with the impulses coming from Asia. The name of this god is Aton/Aten, and he is not limited to a single country or people. Then a young pharaoh comes to power in Egypt in 1379 B.C. Like his father he is called Amenhotep/Amenophis (IV) (Amenhotep = 'Amon is satisfied') in the beginning. Later on he changes his name to Akh-en-aton. He tries to impose a new belief system on his Egyptian subjects, which is in contrast with the traditions and habits of thousands of years. This new belief system is an orthodox monotheism, the first example of its kind in history. Amenhotep's rule lasts 17 years (1379-1362 B.C.). Following his death this new belief system meets its end abruptly, and anything and everything that belonged to this 'heretic' ruler is banned.

Each new development must have a basis. From this viewpoint the roots of monotheism in Egypt could be found in earlier times. For a significant period there have been attempts among the priests of the Sun Temple at On (Heliopolis) to develop the thought and emphasize the moral aspect of an universal god. During the reign of Amenhotep III (The father of Akh-en-Aton) worship of the Sun-god seems to have achieved some degree of popularity (This may have been a reaction to the strengthening of Amun of Thebes). A very ancient name of the Sun-god, Aten, Aton or Atum, has regained importance. And the young king Amenhotep IV found a ready movement based on Aten/Aton belief system. Although he was not the first to have initiated this belief system, he became a loyal follower. While all this was going on, Egypt became a world power, and the resultant imperialism found its reflection in religion as universalism and monotheism. This god had to go beyond the boundaries and spread its sovereignty to the occupied lands. Amenhotep IV has never denied his loyalty to the Sun cult.

Amenhotep IV worshipped the Sun not as an object but as a symbol of a divine being whose energy is manifested as rays of light, and he described himself as "first prophet of Re-Horakhte, rejoicing in the Horizon, in his name 'Sunlight which is in Aton.' " The high priest of Aton was called 'greatest of seers'. Instead of the word god Aton is used and god is differentiated clearly from the Sun as a body, and the pharaoh has sanctified the Sun's power to influence the world. The new cult has emphasized the personal nature of the relationship between the god and the pharaoh. No longer anthropomorphic the Sun was depicted as a golden orb shedding rays of light on the king and his queen Nefertiti, each ray ending in a little hand proffering the sign of life, the ankh, to the royal pair. Amenhotep's influence was an energetic intervention. He has introduced for the first time the 'exclusion factor' which transformed the doctrine of a universal god into monotheism. In one of the hymns he says: "O, sole god, there's no other god beside you!" (An identical impression could be found in next believes system). As a result of the reaction amongst the priests of Amun to this new religion Amenhotep's belief system gradually became clear, coherent, unyielding and intolerant. This opposition has risen to such a level in the sixth year of Amenhotep's reign that he changed his name - a part of which was the name of god 'Amun/Amen' to Akh-en-Aton (Akh-en-aton = 'Aton is pleased' or 'It pleases Aton') (Think about the word 'amen' in next believes system: 'amin').

These two words are identical apart from their pronunciation. Could they be a remnant of those days of the god Amun/Amen where the people at communal prayers in the temples were repeating the name of the god Amen/Amun in between the prayers and chanting: 'Amen'. This word could have passed to the next believes system. Akh-en-Aton has removed the name of god, Amun/Amen, not only from his name but also erased it from all the inscriptions. After changing his name he left the city of Thebes, and has established a new royal capital lower down the river, which he named 'Akhetaten' (Akhetaton/Akhetaten = 'The horizon of Aten/Aton') the ruins of which is Tell el-Amarna in our day. He closed all the temples of Amun, worshipping in those temples were banned, all the assets of the temples were confiscated. According to Akh-en-aton what is said about the other gods were all lies, and deception. He totally rejected the illusion of life after death which was very important to Egyptians.

[2025 Editorial Note]

This post was originally written in 2021 during my early exploration of monotheistic roots in Egypt. While many perspectives here remain valuable, I have since integrated more theological and historical depth through Codex DINGIR and other studies. Please read with an open, reflective spirit.

LIGHT RAIL VEHICLE DESIGN CHARACTERISTICS - Low-Floor Car Truck Design

The ends of the 70% low-floor car, including the operator’s cabins, are generally at the same height as a high-floor car, allowing trucks of conventional design under the ends of the car. But it is not possible to use conventional trucks beneath the low-floor portions of the car because the floor would be lower than the elevation of solid axles. The usual resolution is to use trucks that do not have conventional solid axles extending from wheel to wheel. Instead, the four wheels are each connected directly to a u-shaped frame that passes beneath the floor.

Each wheel, lacking a mechanical connection to another, therefore rotates independently and is naturally called an independently rotating wheel (IRW). As an alternative to IRW trucks, at least one manufacturer has developed a truck using conventional solid axles connecting very small diameter wheels. This design also ramps the floor of the articulation body section slightly above that of the floor by the doors. However, small diameter wheels will have a smaller contact patch with the top of rail and thereby increase wheel/rail contact stresses, possibly increasing rail wear and corrugation rates.

Because of constrained space, these special truck designs beneath the center sections of 70% low-floor LRVs are generally non-powered. Propulsion is provided only at the conventional trucks under the ends of the car. However, 100% low-floor cars must provide propulsion at trucks under the low-floor, and carbuilders have come up with several ingenious, albeit complex, methods for doing this. Because of this complexity, 70% low-floor cars using conventional power trucks have generally been considered more reliable than 100% low-floor cars.

Nevertheless, the 100% low floor LRV has been almost exclusively adopted for new vehicle purchases by in-street tramway type operations in Europe and also by some of the stadtbahn-type operations. As of 2010, the first 100% low-floor LRV specified in North America was being produced for Toronto Transit Commission. The Toronto cars are also specified to negotiate a 36-foot [11-meter] radius curve. The degree to which the carbuilder succeeds in meeting the Toronto requirements may radically change preferences for light rail vehicle design.

As of 2010, the lowest 100% low-floor LRV was the Vienna Ultra-Low-Floor (ULF) car, with the floor a mere 200 mm [about 8 inches] above the top of the rail. The traction motors of the ULF car are mounted vertically within the articulation sections. As of 2010, this design has not been adopted elsewhere.

The conventional trucks that are under the end body segments of 70% low-floor cars rotate with respect to the carbody. By contrast, the trucks under 100% low-floor LRVs generally do not rotate and are, for all practical considerations, rigidly fixed to the carbody. This configuration has resulted in vehicle designs that are radical departures from high-floor and partial low-floor designs and vehicles that have significantly different steering and curve negotiation characteristics.

MYTHS RELATED TO NILE

Nile naturally occupies a large place in the mythology of Egypt. Mortuary rituals and myths of the Osiris cult, as well as the cult of Re are bound up with the myths connected to the Nile. The river was worshipped as a god under the name of Hapi. There is a famous statue of the Nile-god in the Vatican Museum which represents the god reclining, holding ears of corn and a cornucopia, and surrounded by sixteen children, each a cubit high.

This symbolizes the fact that if the Nile flood fell below sixteen cubits there would be famine. On a tomb at Abydos we have a representation of the two Niles bringing papyrus, lotus and various kinds of food and drink. The myth of the two Niles is contained in Akh-en-aton's famous hymn to the Aton/Aten, or Sun-disc. In this myth Aton creates two Niles, one in the underworld and another in the heavens above. Aton brings forth the underworld Nile to sustain the people of Egypt.

The purpose of the heavenly Nile is to provide water to the foreign peoples. But the most important and significant aspect of the myths related to the river Nile is the one associated with the Osiris myth. In a hymn to Osiris Rameses IV says "You are the Nile, gods and men live from your outflow." One of the elements in the Osiris myth is the drowning of Osiris and his recovery by Isis. Plutarch tells us that in the month of Athyr the priests used to go down to the river by night and fill a golden vessel with sweet water.

As they did so, the people present in the ceremony cried 'Osiris is found'. Both the drowning and the finding of Osiris in the Nile play an important part in the seasonal rituals of Egypt.

LIGHT RAIL VEHICLE DESIGN CHARACTERISTICS - Low-Floor Cars—General

In response to these issues, low-floor light rail vehicles were developed. In a low-floor car, either the middle portion or all the vehicle floor is positioned a short distance above top of rail. A typical dimension is 300 to 350 mm [about 11.7 ¾ to 13 ¾ inches]. This enables station platforms to be little more than sidewalks that are just slightly higher than normal above the street surface, making them much more practical for construction in congested urban areas.

Since about 1995, the partial low-floor car (often called a “70% low-floor” LRV) has become the preferred design for North American light rail transit systems that need level boarding from low platforms. The partial low-floor car has some middle portion of the LRV at the lower elevation while the ends of the car are at normal high-floor car elevation. The doors are usually all in the low-floor section of the car and the high-floor areas at the ends of the car are accessed by interior steps.

The low-floor area usually represents approximately 70% of the total length of the car, hence the common name. (Boston’s Type 8 LRVs are a notable exception; clearance limitations in the Green Line tunnels substantially restricted the truck center distance so that the low-floor portion of each car is only about 60% of the overall length.)

One advantage of a 100% low-floor LRV is that the low profile of the cab and windshield increases the probability of eye contact between the operator and persons on the trackside. A corresponding advantage to a high-floor or 70% low-floor LRV is that the operator’s higher seating provides a better view of the trackway ahead, which could be an advantage in some traffic situations.

One possible issue with low-floor cars is that they maintain very close clearance to rails. With worn-out wheels, the vertical clearance between the underside of truck-mounted equipment and the plane of the top of rail can be a little as 35 mm [1 3/8 inches]. This could affect the use of some trackwork and signal system appliances mounted between the rails. The vehicle clearance also must be considered in design of tracks for hilly terrain, where the radius of the vertical curve over the crown of the street must be large. On one project, the low underclearance of the vehicle limited the height of discontinuous floating slabs that could be used, where maximum mass is needed for vibration control.

THOTH AS THE DEPUTY OF RE

Re orders Thoth, the Moon-god, to be summoned before him. When he appears Re tells him that he is to be Re's deputy and give light in the underworld, while Re shines in his proper place in the heavens. This is an aetiological myth intended to explain why the Moon gives light at night.

LIGHT RAIL VEHICLE DESIGN CHARACTERISTICS - High-Floor/Low-Floor LRVs (1 of 2)

Light rail vehicles are built in a variety of designs and dimensions. In almost all cases, they are capable of being operated in coupled trains. Modern LRVs are generally much larger and heavier than their streetcar predecessors and can have axle loads just as large as, or even larger than, so-called "heavy rail" transit vehicles.

Light rail vehicles vary in the following design characteristics:

1. Unidirectional versus bi-directional
2. Non-articulated versus articulated and, for the latter, the location(s) and configuration of the articulation joints
3. 100% high-floor versus partial low-floor (typically 70% or less) versus 100% low-floor
4. Overall size (width, length, and height)
5. Truck and axle positions
6. Weight and weight distribution
7. Suspension characteristics
8. Performance (acceleration, speed, and braking)
9. Wheel diameter and wheel contour
10. Wheel gauge

These characteristics must be considered in the design of both the vehicle and the track structure.

3. High-Floor/Low-Floor LRVs
Getting passengers safely and expeditiously onto and off of light rail vehicles at stations has always been an issue. Time spent at stations—“dwell time”—can be a significant percentage of the overall running time from terminal to terminal. For a conventional “high-floor” light rail vehicle, with steps at the doors that are internal to the vehicle, the delays inherent in climbing up and down steps adds significantly to the dwell time. The various measures necessary to comply with the Americans with Disabilities Act Accessibility Guidelines (ADAAG) means even more delay before such LRVs can resume forward motion.

Level boarding from the platform to the vehicle is clearly the best way to accommodate the mobility-challenged transit rider. Level boarding also reduces station dwell times by making it easier and quicker for all riders, mobility-challenged or not, to board and alight from the LRV. Because of these advantages, heavy rail metro systems have always used level or near level boarding from high level platforms. Following that example, several light rail systems built during the 1980s, in both North America and Europe, incorporated level boarding from high level platforms, largely eliminating the need for steps.

The problem with high level platforms is that they usually can fit alongside of the tracks only if the light rail line is in an exclusive guideway such as a subway tunnel, an aerial structure, or a private right-of-way. High platforms that are the full length of the train (usually no less than 200 feet/60 meters for a two-car train) are generally impractical where the LRT guideway is in an urban street. Urban locations often also have insufficient space for vertical circulation elements to get passengers from street and sidewalk level up to a station platform that would usually be 3 feet [0.9 meter] higher. Moreover, a two- or three-car long high platform will often be very intrusive on the urban streetscape, as well as quite expensive.

Because of such issues, light rail systems that were constructed in the 1980s and early 1990s and included extensive operations in city streets typically used high-floor LRVs that were equipped with steps for patrons to board from sidewalk level. A variety of methods were used to get mobility-challenged persons on and off the vehicles, with mini-high platforms being the usual choice. However, these arrangements were generally less than fully satisfactory. Some means of providing level boarding for all riders without resorting to full-length high level platforms was desired.

THE SECRET NAME OF RE

This is a solar myth which concerns the magical potency of the name of a god. Isis wants to learn the secret name of Re. She thinks she might use it in her magic spells. She creates a snake, places it in the path of Re. Re comes out his palace, and snake bites him. Re is seized by terrible pains. He calls for the gods to a meeting. Amongst them is Isis with her magic skills. Re tells them what has happened to him, and begs Isis to relieve him. Isis tells him, in order for her spell to be effective she must know his secret name. Re tells her that he is Khepri in the morning, Re at midday, and Atum in the evening.

But Isis tells him that none of these is his secret name of power. Finally he reveals his secret name on the condition that it is made known to no god but Horus. Using Re's name of power Isis utters the spell which removes the effects of the snake's poison. The text ends with directions for the use of spell to cure snake-bite.

LIGHT RAIL VEHICLE DESIGN CHARACTERISTICS - Non-Articulated/Articulated (2 of 2)

Particularly in the case of low-floor LRVs, there are many variations on articulation joints, as each LRV manufacturer has devised its own specific design. These hardware variations can affect vehicle clearances since the pivot points of the articulation can be a considerable distance off of the centerline of sharply curved track. Variations in center section design also affect steering and relative roll, which might have some affect on vehicle curving and rail wear, thus influencing rail steel selection, track gauge, and track superelevation. The track designer has little control over this, but the problem is more difficult with low-floor vehicles using independently rotating wheels than with conventional high-floor vehicles equipped with solid axles.

Existing systems contemplating a change to longer vehicles must consider overall train length and the impact that the revision might have on existing station platforms. Longer cars might require either a reduction of the number of vehicles in a train or lengthening existing platforms.

One major LRT system in the United States initially designed their underground LRT stations for four-car trains of conventional two-section high-floor LRVs. When they added low-floor vehicles, trains had to be limited to three of the longer low-floor cars because the subway station platforms could not be economically lengthened. Longer vehicles can affect other infrastructure and systems as well, particularly the layout of equipment within the light rail vehicle maintenance shop.

There is a common misconception that articulated light rail vehicles can negotiate sharper curves than a rigid body car. This is not true. Rigid cars can negotiate curves that are as sharp, and even sharper, than an articulated vehicle. However, rigid cars are limited in both length and passenger capacity, primarily because the lateral clearances required in curves increase dramatically as the distance between the trucks increases. Where lateral clearances are not an issue, rigid body cars can be appreciably cheaper to procure and maintain than articulated cars of similar passenger capacity; however, this is a distinct exception to the normal circumstances.

In North America, modern non-articulated light rail vehicles are used only in Philadelphia, Buffalo, and Toronto, but, as of 2010, those fleets, which are all high-floor designs, are in their third decade of operation. Outside of North America, the light rail system in Hong Kong and several cities in the former Soviet Bloc have continued to purchase rigid body cars, most likely for reasons peculiar to those systems. Therefore, while thousands of single unit, single-end trams, many of them of designs derived from the North American PCC car, still operate around the world, it is virtually certain that the LRVs for any new system will always be high-capacity, multiple-section, articulated cars.

THE SLAYING OF APOPHIS

The serpent Apophis is the enemy of Re. In one of the texts Seth is the agent of victory. Refresh your memory. Marduk is the agent of the gods in the conquest of the dragon Tiamat in the Akkadian myth.

In another text the gods whom Re has given birth employ their magical powers to destroy Apophis. We have an interesting parallel here with the victory of Marduk over dragon Tiamat at the Babylonian New Year Festival.