Stone cut design, either SC-rough, either SC-final, of all the stones have been performed trough the use of charts that have been organised in four different books (for a global amount of 45000 data). These books contain both the dimensions of the stones and all the co-ordinates of the intrados and extrados curves of the bridge arch. Books have been subdivided mainly as follows:

• stone cut - book 01 – SMS-A Stari Most Stones – Arch
• stone cut - book 02 – SMS-A Stari Most Stones – Arch
• stone cut - book 03 – SMS-A Stari Most Stones – Arch
• stone cut - book 04 – SMS-B Stari Most Stones – Bridge

In the above images some schedules taken from each book have been represented in a preview format. Contents of each book is here next briefly described:

book 01 (about 8000 data): stone cut of all the stones of the load bearing arch, trough a management by row; each schedule contains the following sections:

• coding
• schematic drawing of the arch row with reference dimensions
• on site final cut dimensions
• quarrying dimensions and volumes
• reference co-ordinates

book02 (about 12000 data): stone cut of all the stones of the load bearing arch, trough a management by stone; each schedule contains the following sections (for each stone):

• coding
• on site final cut dimensions
• quarrying dimensions and volumes

book03 (about 17000 data): co-ordinates of all the stones of the load bearing arch, trough a management by stone; each schedule contains the following sections (for each stone):

• coding
• intrados and extrados co-ordinates

book04 (about 8000 data): stone cut of all the stones of the bridge, trough a management by stone; each schedule contains the following sections (for each stone):

• coding
• on site reference cut dimensions
• quarrying dimensions and volumes

The use of the above books and charts requires a preliminary study and analysis of the organisation of data and requires to follow instructions that are reported in next paragraphs.

Any misuse or wrong interpretation of the books may lead to insurmountable difficulties in respecting the geometry of the former bridge; General Engineering, for the above reason, is available for any further explanation of the data, of their meaning and of their correct use: a direct technical meeting is anyhow desirable in order that no misunderstanding takes place. General Engineering will not be responsible of any incorrect use of the stone cut dimensions and co-ordinates contained in the mentioned books.

7.12.1 Stone cut - book 01 - SMS-A

The book should be used for the following purposes:

• stone rough cut (SC-rough) of the voussoirs of the load bearing arch (SMS-A);
• stone final cut (SC-final) of the voussoirs of the load bearing arch (SMS-A);
• geometry determination of the bridge intrados and extrados curvatures.

This book has been worked out managing the stone cut by rows, which means that some simplifications have been introduced in order to reduce at the highest level as possible the number of dimensions and co-ordinates used. The accuracy is anyhow guaranteed but volume of stone, for rough stone cut (SC-rough) is globally higher of about five cubic meters, being all the rough blocks in a row assumed with the same front face size. Measures and co-ordinates for final stone cut (SC-final) are limited only to the ones of north and south elevation outer faces; measures have been given also for row plan and its deviation. Stones which are located in between the two edge voussoirs may be determined, for their length trough the use of annexed dimensions, and for what concern the faces, trough on site interpolation (using ropes or any similar reference collimator).

warning:

Stone final cut measures are reference dimensions, (given for all the rows and all the voussoirs), that define a theoretical volume which does not consider the thickness of joints, (measures are referred to the joint center line), and which has been worked out by linking with straight lines the extreme faces of each row. This means that this volume with all its dimensions will have to be followed as a reference limit and all the geometrical variations between north and south elevation will be performed by small steps of adjacent voussoirs and not by straight ideal profile which would make the stone cut much more complex and the result quite different from the former bridge.

• schedule number (1-111): number of the schedule (as many as the rows of the load bearing arch);
• first intrados joint number (1-111): number of the first intrados row joint starting from east origin (as many as the rows of the load bearing arch);
• intrados row roman number (I-CXI): roman number of the rows (following numbering of 1955);
• number of stone in a row (2-5): number of stone voussoirs contained in current row.

The above schematic drawing is an axonometric view of the current row and varies in the schedules depending on the number of voussoirs contained in the row (2-5) and there are drawn all the dimensions that have been used in the chart with variable conventional names. All the voussoirs are here conventionally represented of identical size as a scheme obviously not to measured and not in scale.

section 03 - on site final cut dimensions:

Reference measures to be used for stone final cut (SC-final), if the simplified management by rows is chosen. Measures are here reduced to the minimum number as possible. Measures are given in centimetres and joint tolerance is equal to zero.

• north side: dimensions of north front face of current row;
• south side: dimensions of south front face of current row;
• row plan: dimensions of the row plan (real dimensions of the row due to deviations); the variable "dev" is the deviation from row plan of the vertex I_1s assuming all the other intrados points belonging to a single plan: the measure may be used to manage the rotation of the voussoirs from north to south along one row;
• current row stones: length of single stones in a row starting from north to south and assuming joint equal to zero (as for all the others dimensions); the variable "nov" is the number of voussoirs in current row.

• stone face: is a model face shape, wide enough to be suitable for all the voussoirs of a row, (this simplification will cost about 5 cubic meters for all the bridge arch, being the size of faces in a row quite constant);

• current row stones: length of single stones in a row starting from north to south; the variable "nov" is the number of voussoirs in current row;

• stone volumes: volume of single parallelepiped block; total volume of the row is given as well.

Reference co-ordinates to be used for wooden deck and centering layout and positioning on site. First group of co-ordinates is given in three dimensions with the origin located in the north east arch springer (over the impost level) and x and y axis laying on the elevation plan. Second group of co-ordinates is in two dimensions and is given only for the first row joint (starting from east to west): origins of north side is located in north east arch springer while for the south side is located in the south east arch springer. This second group of co-ordinates may be used during the construction and layout of the wooden deck. Co-ordinate should be used only after verify on site.

7.12.2 Stone cut - book 02 - SMS-A

The book should be used for the following purposes:

• stone rough cut (SC-rough) of the voussoirs of the load bearing arch (SMS-A);
• stone final cut (SC-final) of the voussoirs of the load bearing arch (SMS-A).

This book has been worked out managing the stone cut by single voussoirs, which means that measures have been given for all the stone faces. The accuracy is equal to the previous method (book 01) but more dimensions have been given in order that even inner voussoirs could be defined. For what concern rough stone cut, (SC-rough), it has been worked out a parallelepiped block for each voussoir that best suits the final voussoir and minimise the use of stone (5 cubic meters of stone will be saved following this book).

warning:

Stone final cut measures are reference dimensions, (given for all the rows and all the voussoirs), that define a theoretical volume which does not consider the thickness of joints, (measures are referred to the joint center line), and which has been worked out by linking with straight lines the extreme faces of each row. This means that this volume with all its dimensions will have to be followed as a reference limit and all the geometrical variations between north and south elevation will be performed by small steps of adjacent voussoirs and not by straight ideal profile which would make the stone cut much more complex and the result quite different from the former bridge.

• schedule number (1-111): number of the schedule (as many as the rows of the load bearing arch);
• first intrados joint number (1-111): number of the first intrados row joint starting from east origin (as many as the rows of the load bearing arch);
• intrados row roman number (I-CXI): roman number of the rows (following numbering of 1955);
• number of stone in a row (2-5): number of stone voussoirs contained in current row.

section 02 a - on site final cut dimensions:

These Reference measures may be used for stone final cut (SC-final), if the detailed management by single voussoirs is chosen. Measures are here defined for each arch stone. Measures are given in centimetres and joint tolerance is equal to zero.

• north side: dimensions of north front face of current stone in current row;
• south side: dimensions of south front face of current stone in current row;
• block plan: dimensions of the block plan (real dimensions of the arch stone due to deviations); the variable "k" is the reference thickness of the voussoir related to the thickness of the whole arch.

section 02 b - quarrying dimensions and volume:

Reference measures to be used for stone rough cut (SC-rough), if the detailed management by arch stone is chosen. Measures are here enough to define all stone voussoirs. Measures are given in centimetres and cubic meters (for volumes). Quarrying tolerance is a minimum of cm 3 each side.

• quarrying dimensions: three dimensions are given in order to define a parallelepiped block of stone wide enough to contain the final voussoir with the planned minimum tolerance, (Bqt=base, Hqt=height, Kqt=thickness);
• block volume: volume of single parallelepiped block.

note for section 02:

Section 02 is repeated in the chart five times, as many as the maximum number of voussoir that are contained in a single row; this of course implies that, being each schedule representative for one arch row, some of the charts that contain a lower number of stones will have from 1 to 3 of these sections completely empty (values equal to zero).

Numbering of arch stones is given on the left of section 02:

• first number is row number and is coherent to the schedule number;
• second number is the arch stone number (1-5) which goes from north to south (stone number one is on the north elevation side, and the others follow progressively towards the south elevation).
• Id number is an identification number and it is of little use for the work (it has been used for managing of data).

7.12.3 Stone cut - book 03 - SMS-A

The book should be used for the following purpose:

• geometry determination of the bridge intrados and extrados curvatures.

This book has been worked out managing the co-ordinate calculation by single voussoirs, which means that co-ordinates have been given for all the center lines of the joints. The accuracy is equal to co-ordinates contained in book 01, but more co-ordinates have been given in order that even inner voussoirs could be defined.

warning:

Co-ordinate should be verified by check on site of relative position of the four arch springers. Inner co-ordinates should be considered as reference points since defining the theoretical volume of each row.

• schedule number (1-111): number of the schedule (as many as the rows of the load bearing arch);
• first intrados joint number (1-111): number of the first intrados row joint starting from east origin (as many as the rows of the load bearing arch);
• intrados row roman number (I-CXI): roman number of the rows (following numbering of 1955);
• number of stone in a row (2-5): number of stone voussoirs contained in current row.

Reference co-ordinates to be used for wooden deck and centering layout and positioning on site. Co-ordinates are given in three dimensions with the origin located in the north east arch springer (over the impost level) and x and y axis laying on the elevation plan.

In this book co-ordinate are given for all the points that define the center lines of all the joints of the load bearing arch. Co-ordinate should be used only after verify on site.

note for section 02:

Section 02 is repeated in the chart five times, as many as the maximum number of voussoir that are contained in a single row; this of course implies that, being each schedule representative for one arch row, some of the charts that contain a lower number of stones will have from 1 to 3 of these sections completely empty (values equal to zero).

Numbering of arch stones is given on the left of section 02:

• first number is row number and is coherent to the schedule number;
• second number is the arch stone number (1-5) which goes from north to south (stone number one is on the north elevation side, and the others follow progressively towards the south elevation).
• Id number is an identification number and it is of little use for the work (it has been used for managing of data).
• Dy0: is the deviation for current stone concerning the row joint with index 0
• Dy1: is the deviation for current stone concerning the row joint with index 1

deviation dimensions may be used to manage (trough the use of the wooden wedges) the rotation of the voussoirs from north to south along one row.

7.12.4 Stone cut - book 04 - SMS-B

The book should be used for the following purposes:

• stone rough cut (SC-rough) of bridge stone elements: spandrels, cornices and parapets (SMS-B);
• stone final cut (SC-final) of bridge stone elements: spandrels, cornices and parapets (SMS-B).

This book has been worked out managing the stone cut by single stone block. The book is subdivided in different sections that are here next listed:

SMS-Bsp_ne spandrel stones north elevation east side

SMS-Bsp_nw spandrel stones north elevation west side

SMS-Bsp_se spandrel stones south elevation east side

SMS-Bsp_sw spandrel stones south elevation west side

SMS-Bcs_north cornices stones (upper and lower) north elevation

SMS-Bcs_south cornices stones (upper and lower) south elevation

SMS-Bpa_north parapet stones (upper and lower) north elevation

SMS-Bpa_south parapet stones (upper and lower) south elevation

For each stone element of the bridge (SMS-B) it has been worked out the smallest parallelepiped that could contain it. This parallelepiped dimensions are the final cut dimensions that are given in charts; any eventual additional cut is defined in the drawings as well as the exact location of the stone. Therefore final cut (SC-final) given in book 04 is most of the times not exhaustive except for those stones which have a parallelepiped final shape: this of course is not the case of all the cornices and parapets.

Rough stone cut (SC-rough) has been worked out by adding the quarrying tolerance to all the dimensions of the final shaped blocks: 3 centimetres for each side = to 6 centimetres for each dimension.

Thickness of spandrel, cornice and parapet elements have been given by range values being these dimensions unknown and quite variable from the study of the bridge transversal section. Design approach trough range dimensions for the undetermined dimensions is one of the basic philosophical choice of this rehabilitation design and it is aimed at reproducing the same quantity of randomly that was proper of the former structure. Criteria adopted for range dimensions are results of observations of the ancient bridge remaining portions and are here next resumed:

Stone book 04 is not enough to complete the stone final cut: SC drawings are required.

Stone rough cut (SC-rough) dimensions of thickness are evaluated with the following criteria:

Stone final cut measures are reference dimensions that define a theoretical volume which does not consider the thickness of joints, (measures are referred to the joint center line).

• type: may be spandrel, cornice and parapet depending on the content of the schedule;
• elevation: may be north or south elevation being the bridge oriented that way;
• side: (used for parapets only) it is referred to half of the elevation: may be east or west side;
• code: it is the conventional code used by General Engineering for the group of stones which are listed and dimensioned in current schedule.

section 02 a - additional coding references:

Additional codes are provided and here next described:

code: code: it is the conventional code used by General Engineering for the group of stones which are listed and dimensioned in current schedule;

num: is the progressive number of the group of stone: with this number it is possible to locate the stone also on the drawings and to have documentation on any additional cut;

type: may be spandrel, cornice and parapet depending on the content of the schedule;

sub: (used only for cornices) subtype: may be upper or lower depending on the analysed cornice;

elevation: may be north or south elevation being the bridge oriented that way;

side: (used for parapets only) it is referred to half of the elevation: may be east or west side;

section 02 b - on site final cut dimensions:

These Reference measures may be used for stone final cut (SC-final). Measures are here defined for each arch stone. These dimensions are the final cut dimensions but any eventual additional cut is defined in the drawings as well as the exact location of the stone. Measures are given in centimetres and joint tolerance is equal to zero.

• base (b): dimensions of the base of the element (side that will lay over other stones);
• height (h): dimensions of height of the element (side adjacent to other stones);
• thickness (t): Thickness of the element given by range dimensions (it means that it must randomly varies in the range depending on the case, level location, availability and on alternation of the ashlar blocks thickness).

section 02 c - quarrying dimensions and volume:

Reference measures to be used for stone rough cut (SC-rough). Measures are here enough to define all stone blocks. Measures are given in centimetres and cubic meters (for volumes). Quarrying tolerance is a minimum of cm 3 each side.

• base (bqt): dimensions of the base of the element + 2qt (side that will lay over other stones);
• height (hqt): dimensions of height of the element + 2qt (side adjacent to other stones);
• thickness (t): Thickness of the element given by an average value +2qt (it means that it must randomly varies in the range depending on the case, level location, availability and on alternation of the ashlar blocks thickness).

• block volume (vqt): volume of single parallelepiped block assumed with thickness average value

note for section 02:

Section 02 is repeated in the chart six times, as many as the schedule could contain. Numbering of block stones is given on the left of section 02.

Moreover it is important to point out that the thickness-average-dimension "t" is an indicative value that should vary in the thickness-range. For instance a spandrel block which has:

• t range = cm60<-> 85
• t average = cm79

actually should be in the range of cm(60+6)« (85+6) = cm66« 91 and anyhow it could be even better to have it in an higher range cm(70+6)« (85+6) = cm76« 91 (because bigger blocks were more frequent in the layout). The stones shouldn’t be all of cm79 that is an average indicative dimension.

For what concern the thickness of the parapets it has to be underlined that quite often the parapets had a profile which was thicker at the bottom than at the top. For the above reason the proposed average thickness of cm29 will let in some points a smaller quarrying tolerance and therefore it is desirable not to reduce it during the stone rough cut.

Finally stone SMS-Bsp_nw 75 has to be changed as follows:

h=24.3 -> h=29

author of the text: arch. Manfredo Romeo – other contributes have been mentioned in related paragraphs

drawings: arch. Paola Marrone  arch. Alessio Talarico    -   sketches: arch. Manfredo Romeo

database management: arch. Manfredo Romeo  - arch. Giovanni Anzani

software development and calculation: ing. Francesco Cenni - ing. Niccolς Baldanzini

yard consultant: Bruno Bonuccelli