The Grand Gallery





Its dimension is very impressive: not the length only, 47,84 m., but even the height, 8,60 m. from the central groove bottom to the ceiling: in the section, perpendicular to the slope, 7,70 m.
The gallery floor, the one aligned to the passage going down to the junction we’ve just spoken, has the right size to contain a block group similar to the one chosen like a sample before, having the same width of the ascending passage.
In the passage side walls, there are two sidewalks, 1 c. (52,5 cm.) wide and 1 c. high from the passage floor. The maximum width is 4 cubits (2,10 m.).
I’m firmly convinced that, inside the central groove, the granite blocks had to slide down to lock the entrance, while in the two sidewalks had to take place two groups of aligned stand workers. The side walls rise vertically for 1,80 cm. (161,5 cm. in the perpendicular section) and in there they start getting narrower .
The first two block rows are simply placed one on the top of the other to allow the people working on the sidewalk; the narrowing starts by the third row, 7,5 cm. each side and it goes on, same size, by the next rows: this is the overhang or corbelled technique. Using this technique, it is possible to make a structure capable of being resistant to a very big compression strain.
This technique will be improved during the next centuries to find expression in the Roman Arch.
These are the first ingenious attempts to protect a cavity from the weight above.
It’s possible to see chambres built in such a way, overhanging all the four side walls, at Meidun, in the Red and also in the Double Gradient Pyramids.
Leaving the structural calculation to someone else, let’s have a look of this very extraordinary ascent way.
Starting exactly at the Quadrivium, where the ascending passage ends, it is possible to find, in the lateral sidewalks, a series of small twin pits, dug near the walls (there is a pit, at the same elevation, on both the sidewalks – see Grand Gallery picture).
These pits have a parallelogram shape, having the long sides parallel to the gallery slope and the short sides vertical like the gravity force direction (see. Niche + Pit Dwg).












All the pits have the same depth, perpendicular to the sidewalk equal to 17 cm. (2 palms + 1 inch), but the longer side has different length: we may find short twin pits (1 c = 52,5 cm) and long twin pits (1 c + 1 p = 60 cm) arranged in a alternating way, except the first two rows (4 pits) which are both short.
In the Quadrivium Dwg. above, the “P” shows the short and the “G” the big pits.
To summarize, starting from the point “ zero “ (see Great Gallery Dwg) there are two short twin pits (P), then two twin short again, followed by two twin long pits (G) and then, going up, a couple of short followed by a couple long and so on; the last one, long type, is at 82 cm from the big step at the end of the Gallery. We have two more short pits, perfectly prismatic, in the top landing, placed back the step, near the south wall.
However we have more complications.
In total there are 28 twin pit rows, but, forgetting the first two and the last, in the top landing, all short, the remaining 25 central twin pits have a distinctive feature: at the middle of every pit, there is a niche, dug in the wall, having a vertical right trapezium shape, the sloping side at the sidewalk level, and the vertical sides parallel to the gravity force direction, that means oblique to the gallery floor. All the niches have the same size: 60 cm high (1 c + 1 p), 27 cm wide (½ c) and 22 cm deep (3 p). They are filled by small trapezoidal limestone pillars, of poor quality and undersized material, kept in position by a bad quality mortar and the lower niche side is coplanar to the sidewalk floor (see. Niche + Pit Dwg).
The seventh niche on the right side, going up, is empty, because someone had the pillar removed (and probably also at the left side, then refilled by a recent restoration work). By this way it is possible to see one more detail: the horizontal high edge of the niche and the low vertical one (north side), have been perfectly smoothed as per a particular angle (see. Niche + Pit Dwg).
I have to explain now that, in my opinion, all the well finished details had been planned in the original project. On the contrary, all the rough works, made hurriedly by chisel, were adjustments to get around an unforeseen difficulty.
Thinking in this way, I imagine the smooth edges of every niche had a precise purpose in the original project. There are also a rushed chiselling affecting the side wall, including the small pillars, in the 25 central niche areas, removing about 1 or 2 cm of material from a rectangular area, which has the long sides parallel and the short sides perpendicular to the sidewalk slope. The long side of the chiselling area is wider than the niche and it includes the pillar; it is also longer than the pit below and it raises from the sidewalk floor for about 20 cm (but I have to carry out some more checks on site) (see. Niche + Pit Dwg).
One more detail: in the Grand Gallery, at half height, in both the side walls and all along its length, there is a groove, 16 cm high and 2 cm deep. Again it is possible to see a well finished area and some rushed works in the upper side of it and perpendicular to the gallery slope. I suppose some wooden planks had been inserted in the grooves to build an intermediate floor to store all the working material and tools on it and hanging the oil lamps below.
A small summary now: going up: two rows of short twin pits, without any niche; 25 rows of twin pits, alternating long and short, with niche, including pillar, and chiselling in the side walls; back the big step, in the top landing, a couple of short prismatic pits, without any niche.
The full length of the Grand Gallery is 47,84 m, from north to south wall. This is not a standardized measure (that means a cubit multiple) and I was surprised of it. I tried a new approach to this problem: the top landing length is 155 cm (3 c); the big step is 90 cm high (1 c + 5 p). Using Pythagoras theorem, the hypotenuse of this triangle is 1,79 m: subtracting it from 47,84, the result is 46,04 m. This is the floor length between the sidewalks and 46 m are exactly equal to 88 cubits :
Hemiunu planned the working length of the slope usable for the granite blocks going down.
About the Grand Gallery height, I could not find any standardized measure, but I was not surprised:
It is reasonable to fix whole measures while we are planning a piece of work, but the results are not unit multiples often, specially if none takes care of it.
I want to remember that something had been fixed anyway: the ceiling width (2 c), the overhang number (7) and their size (1 p).
Any problem should have a degree of freedom, sometimes!

Now I’m going to explain, in a reasonable way, why the Grand Gallery is 88 cubits long exactly.
Hemiunu spent much time projecting this part of the pyramid. In addition there are more structural complications, I did not speak yet about, it could let the modern architects astonished.
The Grand Gallery ceiling is 2 cubits wide, exactly the half of the ground floor width. In addition, the big limestone blocks of the ceiling are installed transversally to the Grand Gallery to avoid an excessive weight which could have caused the blocks sliding down. The last block row up is set out in a longitudinal way to reduce the weight force on the lower limestone blocks. These upper longitudinal blocks have a sequence of small grooves, where the ceiling blocks fit in.
Also all the overhang blocks could slide toward the Grand Gallery lowest end. This is avoided because the stress intensity is alternatively released on the transversal blocks of the north wall or on the farther supports, crossing the wall, which, in this case, will have narrow blocks perfectly inserted between the stringer walls.
I know it isn’t so easy to explain, specially in English; I may add a simple drawing, but it will be complicate as well.
My goal, anyway, is to convince you that everything has been planned by the designer.
Many Great Pyramid experts are convinced the project has been modified during the construction. This is a foolish hypothesis, because the Grand Gallery installation, in the pyramid body, required many structural pre-settings, starting from lower building levels (I have a very interesting idea about).
Now, please pay attention: we are going back to the Grand Gallery 88 cubits length. During the explanation, while you understand a matter, more questions will arise, as I did.
During six months time I had a kind of pyramid delirium: I slept having a small voice recorder close to my bed and, in the night time, I spoke in a soft voice under the blanket, not to wake up my wife who thought I was getting mad, to record on the tape any new idea about.
I have a logic answer for any question you may ask, also for the smallest details and, little by little, I’ll show you.
The book, I’ve just written, deals with it. Any detail, even the smallest, is logically inserted in the main project. You may agree with me or not: if you will read it like a novel, I’m sure questions will rise in your mind. Sometimes the border between fantasy and reality is not so defined: rejecting the impossible, what’s remaining …….!
Inside the Grand Gallery, the average distance between the small pits (and niches) centre is 3c + 2p (172 cm about), equal to the standard length of the granite block we assume before ± 1finger.
Now that means the GRand Gallery has been built like a big feeder, containing 25 blocks, which had had to go down the descending corridor to seal the pyramid, finally.
Why 25 blocks? There are 27 twin niches. If we consider the hypothesis that the niches were the housing for the wooden beams to tight the blocks, they should have been 27. But my point of view is different.
The first pit-niche, close to the big step up, is only 82 cm from the step edge and it could not keep in position any more block because there is not space enough to insert it above.
On the contrary, 82 cm + half a pit (30 cm) - 52,5 x tan 26,5 (26,17 cm) = 85,8 cm, is equal to half block length.
I had to subtract 52,5 x tan 26,5 because the block prismatic shape and the highest edge of the block can lean against the low edge of the big step only, far away from the sidewalk end and this distance is equal to I showed above.





If we suppose every pit-niche is linked to the block central section, we have just 25 blocks.
In this case, what’s the use of the lowest four pits (two couples) for? And the upper two?
Now it is necessary to introduce some physic concepts and, in particular, the vector properties.






If we calculate the volume of the standard granite block, we will have 1,7 x 1,19 x 1,04 = 2,18 m³.
The granite specific weight is 2,7 about; so the block weight will be 2,18 x 2,7 = 5680 kg !!
Imagine the block is at the Grand Gallery bottom, waiting to be lifted, by the workers, to the big step up.
Drawing a right triangle, with a low angle of 26,5° (the cathetus ratio is 2:1).
Putting the block on the triangle hypotenuse and decomposing the weight vector as per normal and parallel planes, we will find, using a trigonometry calculation:
Normal Force (NF) = 5680 x cos26,5° = 5680 x 0,895 = 5083 kg
Tangential Force (TF) = 5680 x sin26,5° = 5680 x 0,446 = 2534 kg
The TF is parallel to the hypotenuse and the direction is down, trying to let the block sliding.
But there is also the Friction Force (FF) and, because the equilibrium is very close to the instability, it is possible to assume the friction force equal to the tangential force value (just a light push ……).
If we need to lift the block up to the slope, about 5000 kg force will be necessary (2500 kg TF + 2500 kg FF – see vector dwg.)
Now the question is: how many workers are necessary to drag the block up?
Let’s suppose we have a special team of strong people. It is logic to assume that every people may pull about 30 kg average weight, specially if the effort continues for a long time.
5000 kg / 30 kg = 166 ….. let’s say 170 workers.
It is a small crowd! Besides we have to add more people: foremen, pull rope men, lighting men, water supplier, etc., about 200 people working inside the Grand Gallery at the same time.
30 people could have positioned everywhere, but the remaining people must have a fixed place to stay during the lifting operation: the sidewalks, 85 people each side.
If we suppose a cubit length is enough for a man, we will have a length of 85 cubits (44,6 m) instead of 88 cubits (the full Grand Gallery length). I don’t think that is by chance!
In this way, we may suppose that Hemiunu planned to employ 88 workers each side, to reduce the single effort to 28 kg only (I don’t know the weight units of the Ancient Egyptians).
I checked with the students in the school where I teach, and I can say that a cubit is enough for a man working in the right position, in a very skilled team, the feet placed like a fishbone (maybe a little bit tight, but not so bad).
Stated that, it is plausible to fill the Grand Gallery by the most blocks it is possible to put in: 25 (for reasons I will speak later on, the Quadrivium area had to be free from the blocks to enter the Queen’s Chamber).
Now, someone could ask: why working in so bad condition? It was possible to insert the granite blocks during the construction, while the pyramid top had still to be erected?
There are two reasons, one much more important than the other.
Now I’ll speak about the least important, you have to wait a little more for the rest.
It had been a very big mistake to put the blocks in the feeder before: Hemiunu knew very well the pyramid could have small settlements during the erection and if any small step may occur in the Grand Gallery slope floor under the granite blocks ……!
Nothing at all must prevent the blocks from sliding down at the right time!
Moreover there are signs of adjusting works made subsequently. A continuous check of the alignment had been carried out
Going back to the first block, positioned at the Quadrivium : there are 170 workers to pull it up the Grand Gallery ramp, plus 30 helpers, and a very little air supply (don’t forget the oil lamps).
As I said there are short and long pits alternatively and this is due to the very little air quantity for so many people working inside.
Going on step by step, first we have to calculate the volume of the available air :
- King’s Chamber = 320 m³
- Grand Gallery = 700 m³
- Ascending Passage = 50 m³
- Horizontal Passage = 42 m³
- Queen’s Chamber = 165 m³
The total is 1275 m³ (I didn’t take into consideration the Descending Passage and the Subterranean Chambre because I suppose that air not available, even if ……).
Of course it is not possible to imagine all the 1275 m³ of fresh air available at the working time (people need time to be in position) and to consume the 100% of it ; also the air ducts can’t help too much the 200 people air request.
I got information: a sportsman, during a continuous effort, needs from 100 to 200 liters of air per minute.
Let’s take the small value, not to exaggerate.
200 people x 100 liters / min. = 20.000 liters / min.
1.200.000 liters / 20.000 liters / min. = 60 minutes !
Just one hour theoretically, really 30 minutes about (anyway, there is a small air circulation).
Surely Hemiunu knew the problem: the Egyptians were already skilled underground tomb builders. So he planned any single detail to minimize the working time.
When the block starts moving up, all the pulling workers are in front of it, but as the block goes up, the number of the pulling workers will decrease, because the people in lower position cannot help.
The Egyptians did not know the wheel, but they prepared hard stones with a proper groove to be used like a rubbing pulley, providing they were wet continuously during the pulling operation.
In this way all the workers could contribute to the pulling effort.
As per my reconstruction, the pulley stones were put on the sidewalk floor, inserted in special wooden (or limestone) yokes, become firmly stuck in the pits, also during pulling.
The two parts of the device were properly stuck between themselves and the walls by wooden beam sideways, lying on the sidewalk and blocked by nogs (see “ yoke and pulley ” dwg.).






The granite block, parked at the Quadrivium, was safely kept in position by using a special strong rear wooden beam to be stuck in the side pits (the short ones and without any niche).
The rear beam is positioned transversally, at the middle block height, perfectly aligned to the centre of gravity, avoiding any turn over along the high slope. Safety was imperative in that project, any block falling down had been catastrophic. So: Safety First!
I’ve studied a blocking system, using two beams, that could also explain why there are two couples of short pits at the starting point.
Using two beams, it is possible to move the lower beam up the slope, keeping the second one back for safety reasons.
Working in this way, the beam heads had to be suitable for the short type pits, but they could be used for the long ones as well.
I imagine that, while the block was going up, the distance between the block and the back beam were filled by wooden shims to reduce the rebound in case of a rope break.
I have to remember that the job is connected to the air quantity available inside. If the time is very important, it is useless to waste it stopping the block to move the stone pulleys in a upper position. It is impossible to install other pulleys in advance because it needs to move the ropes to the pulleys upstairs.
Better to plan a pulling system suitable to work without any interruption and rope overlap, as Hemiunu did, I suppose.
While the granite block is pulled up, a pair of pulley stones, with the slipping groove higher or lower than the previous one, shall be prepared by a working crew in the next couple of pits upstairs. When the block is close to the working pulley pair, it must be removed and inserted in the next pits, obviously suitable for their size, as planned.
The ropes must be pulled to next pulley pair, without slipping them off and inserting the lacing hole in the pulley before to stick it. A proper rope play, I’ll show you after, lets the workers on the sidewalks, to change the rope, having a continuous pulling, direct or reverse, without moving themselves: the metod is effective.
Now it is possible to understand why there are long pits, suitable for pulley stones having higher slipping groove, and short ones, having lower grooves. The height difference is equal to the rope size, to avoid any dangerous rope overlap or friction and the workers can change easily the ropes to pull because very close to their hands (see “ ropes” dwg.). Moreover the groove width is enough for two paired ropes, because the lower rope shall be closer to the wall than the higher one (see “ back ropes “ dwg.).





In fact I’ve imagined a pulley stone type only, suitable to be used for higher or lower position; this is just an idea of mine, but that is the simplest way really. Maybe ….?
On the contrary two different kind of wooden (or limestone) yokes,
to hold back the pulley stones, are necessary: the higher ones shall be longer as well, and shall be inserted in the long pits, while the shorter and lower shall be positioned in the small pits. It looks complicate, but it is not : I’ve prepared a small model of it and it works.
There are three rope pairs, wrapping the block back and working simultaneously.
Two rope pairs are necessary for the reverse pulling, we’ve just spoken ; the third one is used for the direct pulling by the workers upstairs (see “ back ropes “ dwg.).
The ropes shall be protected by the block corner abrasion using six wooden grooved devices, because the three ropes. Considering the block is 120 cm high and 52 cm of it are lower than the sidewalk floor, just 70 cm remain : good enough!
I’ve investigate about the kind of ropes used in the Ancient Egypt: a normal coir rope, 6÷7 cm diameter, is strong enough. But I think Hemiunu had used the best ropes of the time, maybe flax made, and a corner abrasion device 2 p ( 15 cm ) high, with a central groove having a width of 1 p ( 7,5 cm ): the right size for the right rope. At the beginning of the pulling operation there is a back safety wooden beam on the floor, so the first rope protection shall be installed above it. This is the reason the first pit-niche pair is right for the higher yokes. When the block starts moving, another pair of corner devices shall be positioned below, just the right position for the lower pulley stone rope.
Starting this time, all the back beams lean against the rope protection devices, instead the granite block directly.
My model makes provision for some wooden spacers, to be installed from the block side to let the ropes away from the block side and aligned to the pulley grooves (see “ back ropes “ dwg.). The spacers don’t need any support, because they will be hold in position by the tightening ropes.
There are two spacer types, one 1 p (7,5 cm) wider than the other, because the ropes working in paired way, so one should be outer (rope A, lower pulley) and the next one inner.

But some devices didn’t work in the right way during the construction. Probably the wooden (or limestone) yokes used to block the pulley stones, didn’t stick in the pits properly and , under stress, they were removed from their pocket. This is the reason Hemiunu, to save his work, planned the rectangular chiseling behind the niches to improve the yoke setting against the wall. In this way the unforeseen problem was over, probably.
To understand the problem better, I’m really sorry, but we need the vectors again.
Around a pulley stone there are two ropes, one lower, parallel to the ground floor, coming from the block back and the other one, going down to worker hands and not parallel to the floor (the worker hands are about 70 cm higher), the two ropes will form an acute angle. Since there is a force acting on every rope (F1,F2), it is possible to have the resultant force acting on the pulley groove (R).
This force cannot be parallel to the sidewalk floor, because it is directed as the angle bisecting line (the two applied forces are equal). This was the mistake!
Now, if I decompose this force in two components, one parallel to the floor (FT) and one vertical (FN), as per gravity field direction, I’ll find that, while the first one is opposed by the pit housing (-FT), nothing opposes the second one (FN?), smaller for sure, but it can reach the 700 kg value, acting on the two pulleys. This is the force taking off the yokes from their slots and this is the reason of the following lateral chiseling. This was the Hemiunu mistake only.





I stop my explanation here, for the moment.
I’ve left many things pending: the niches with the small balusters, the throttling, why there are 3 granite blocks instead of 25, the last pits upstairs and more details I’ve never spoken yet.
If this web site will be successful (I’ll check the visitor number), I’ll go on with it, even if I prefer a professional publisher giving me a chance, with copyright guarantees.
I’ve shown you my way to face the problem, I guess.
My point of view can be questionable of course, but it is based on scientific arguments only, leaving back esoteric hypothesis………
Thank to whom had enough patience to read all of this.

Bye soon (maybe !).


At last I've ended my Grand Gallery wooden model by which I guess to show you what I've just written about.

The scale model is short, because I've compressed its dimension jumping the 20 central twin pits (and niches).

The animation allows to see a granite block going up as I told you before. It is possible to stop the movie to magnify the details.

You can enter the animation clicking here: Multimedia


Efrem Piccin

All the present photos belong to the Photo Archive of my friend Jon Bodsworth: