with reference to the embodiment of shaft wall 101 of fig6 , typically , a floor c - runner 10 and a ceiling c - runner 11 are installed in a substantially parallel relationship , with multiple triangular studs 112 positioned in a substantially perpendicular relationship between the floor c - runner 10 and the ceiling c - runner 11 . the triangular stud 112 of the shaft wall is between the floor c - runner 10 and the ceiling c - runner 11 . the triangular stud 112 has a triangular polyhedron shape comprising three sidewalls defining a triangular bottom perimeter and a triangular top perimeter . preferably , all transverse cross - sections of the triangular stud 112 parallel to the top perimeter and the bottom perimeter are the same triangle . each c - runner 10 , 11 has a horizontal middle wall ( section ) 6 , a first vertical wall 2 , and a second vertical wall 4 ( fig6 ). height h 1 of the first vertical wall 2 and height h 2 of the second vertical wall 4 are about the same . the middle wall 6 forms a substantially planar transverse plane having opposed first and second longitudinal sides each , having a length , and opposed first and second ends , each having a width , wherein the length of each longitudinal side is greater than the width of each end . the first vertical wall 2 extends to the first height h 1 from the first longitudinal side of the middle wall 6 . the second vertical wall 4 extends to the second height h 2 from the second longitudinal side of the middle section . the first vertical wall 2 and the second vertical wall 4 are substantially parallel . the middle wall 6 , the first vertical wall 2 and the second vertical wall 4 form a generally c - shape . unlike the conventional system 1 of fig2 , the shaft wall assembly system 101 of the present invention has no shaft liner panel positioned between the floor runner 10 and the ceiling j - runner 11 , and between each of the studs 112 . points of the fasteners 35 end within a cavity within the triangular stud so they do not contact the inside space 28 of the shaft wall assembly 1 of the shaft wall assembly 101 . there is no need for shaft liner panels to separate the pointed inner ends of the fasteners from the inside space 28 of the shaft wall assembly . located outside the c - runners 10 and 11 are a pair of wall boards 14 and 15 . when fully installed an inner surface of wall board 15 forms the inside of the shaft , while an outer surface of the wall board 14 forms the interior wall of a room . located outside the j - runners 10 and 11 are a pair of wall boards 14 and 15 . when fully installed an inner surface of wall board 15 forms the inside of the shaft , while an outer surface of the wall board 14 forms the interior wall of a room . the embodiment of shaft wall 101 a of fig6 a is substantially the same as that of fig6 but employs j - runners 10 a , and 11 a rather than c - runners . with reference to fig6 a , typically , a floor j - runner 10 a and a ceiling j - runner 11 a are installed in a substantially parallel relationship , with multiple triangular studs 112 positioned in a substantially perpendicular relationship between the floor j - runner 10 a and the ceiling j - runner 11 a . the triangular stud 112 of the shaft wall is between the floor j - runner 10 a and the ceiling j - runner 11 a . the triangular stud 112 has a triangular polyhedron shape comprising three sidewalls defining a triangular bottom perimeter and a triangular top perimeter . preferably , all transverse cross - sections of the triangular stud 112 parallel to the top perimeter and the bottom perimeter are the same triangle . each j - runner 10 a , 11 a has a horizontal middle wall ( section ) 6 , a shorter first vertical wall 2 a , and a taller second vertical wall 4 a ( fig6 ). the middle wall 6 forms a substantially planar transverse plane having opposed first and second longitudinal sides each , having a length , and opposed first and second ends , each having a width , wherein the length of each longitudinal side is greater than the width of each end . the shorter first vertical wall 2 a has a first height h 1 a and the taller second vertical wall 4 a has a second height h 2 a , wherein the first height h 1 a is less than the second height h 2 a . the shorter first vertical wall 2 a extends to the first height from the first longitudinal side of the middle wall 6 . the taller second vertical wall 4 a extends to the second height from the second longitudinal side of the middle section . the shorter first vertical wall 2 and the taller second vertical wall 4 are substantially parallel . the middle wall 6 , the shorter first vertical wall 2 and the taller second vertical wall 4 form a generally j - shape . unlike the conventional system 1 of fig2 , the shaft wall assembly system 101 a of the present invention has no shaft liner panel positioned between the floor j - runner 10 a and the ceiling j - runner 11 a , and between each of the studs 112 . points of the fasteners 35 end within a cavity within the triangular stud so they do not contact the inside space 28 of the shaft wall assembly 1 of the shaft wall assembly 101 a . there is no need for shaft liner panels to separate the pointed inner ends of the fasteners from the inside space 28 of the shaft wall assembly . located outside the j - runners 10 a and 11 a are a pair of wall boards 14 and 15 . when fully installed an inner surface of wall board 15 forms the inside of the shaft , while an outer surface of the wall board 14 forms the interior wall of a room . fig7 is a top cross section of the triangular stud 112 of the assembly 101 of fig6 ( and assembly 101 of fig6 a ). the triangular stud 112 has notches 113 to assist placement . the notches 113 are formed by cutting and bending back wings 113 a ( fig8 ) of metal of the triangular stud at an upper end and lower end of the triangular stud . the triangular stud 112 has a hollow interior . fig8 is a top view of the triangular stud 112 of fig7 placed on a c - runner 110 of the invention . c - runner 110 has a first vertical wall 102 , a second vertical wall 104 , and a horizontal middle wall 106 . j - runner 110 is modified to have indentations 118 on its shorter vertical wall to assist in placing the triangular stud 112 of fig7 in a shaft wall assembly such as that of fig6 or fig6 a . the indentations 118 mate with the notches 113 . preferably the indentations are 6 to 12 inches apart on center ( oc ), typically 8 inches apart oc . fig9 illustrates a top view of a portion of the assembly 101 of fig6 , modified to include the floor runner 110 of fig8 and the wall boards 14 , 15 attached by fasteners 35 to the triangular studs 112 of the invention . however , the indentations of the floor runner 110 of fig8 are omitted in fig9 for clarity . fig1 shows a top view of an alternative embodiment of a triangular stud 142 of the invention without the notches , but having an overlapping corner forming a seam or punch connection 144 . a seam is when two pieces of steel are basically rolled over to connect them . a punch connection would punch out a small section of steel creating a tab that will connect the two pieces of steel . fig1 shows a perspective view of the triangular stud 142 of fig1 having the overlapping corner forming the seam or punch connection 144 and a hollow interior . fig1 is a top view of a c - runner 150 of the invention . c - runner 150 has a first vertical wall 152 , a second vertical wall 154 , and a horizontal middle wall 156 . c - runner 150 is modified to have protrusions 158 on its second wall 154 to assist in placing the triangular stud 142 of fig1 in a modified version of the assembly of fig6 . if desired the invention can employ a j - runner ( not shown ) modified to likewise have protrusions 158 on its higher wall 154 to assist in placing the triangular stud 142 of fig1 in a modified version of the assembly of fig6 a . fig1 is a top view of the embodiment of fig1 further modified to include c - runner 150 a having stand - offs 151 as lifting elements for drainage and to assist in placement of the triangular studs 142 . the lifting elements 151 allow for self - centering of the triangular studs 142 between the c - runners . preferably only the floor c - runner 150 a is provided with lifting elements 151 . however , if desired both upper and lower c - runners may be provided with lifting elements 151 . the triangular wall stud 142 lines up with a respective lifting element 151 . if the wall stud 142 rests on the lifting element 151 , then the wall stud 142 will be centered . these lifting elements 151 are preferably constructed to allow for self - centering of the studs 142 in a vertical direction during installation and when assembled . self - centering means the studs 142 are spaced above the middle wall 156 of the floor c - runner 150 a . if desired the invention can employ a j - runner ( not shown ) modified likewise in a modified version of the assembly of fig6 a . a first end of the lifting element 151 is proximal to the shorter vertical wall 152 and a second end of the lifting element 151 is distal to the shorter vertical wall 152 . at least one triangular stud 142 is positioned on the lifting element 159 . also , preferably the lifting element 151 defines a drain in the horizontal middle wall 156 below the lifting element 151 . fig1 is a side - view cross - section of the c - runner 150 a of fig1 along view xiv - xiv of fig1 including the lifting elements 151 for drainage and to assist in placement . this shows a ramping edge 153 of the lifting element 151 can define an angle “ a ” of between 25 ° and 75 °, preferably about 64 ° with respect to a y - axis parallel to the second upstanding section 154 . the lifting element 151 can have a curved profile as shown in fig1 or form a substantially transverse , top shelf ( not shown ). the lifting element 151 can have a total length k of about 3 to 12 inches . the lifting element 151 can have a height at its open mouth 155 of about 0 . 5 to 1 inch . fig1 is a perspective - view of the j - runner 150 a of fig1 including the lifting elements 151 for drainage and to assist in placement . fig1 is a top view of the embodiment of fig1 further modified to include c - runner 150 b having tabs 161 as a lifting elements for drainage and to assist in placement of the triangular studs 142 . the lifting elements 161 allow for self - centering of the triangular studs 142 between the c - runners . preferably only the floor c - runner 150 a is provided with the tabs 161 as lifting elements . however , if desired both floor and ceiling c - runners may be provided with the tabs 161 . the triangular stud 142 lines up with respective lifting elements 161 . if the wall stud 142 rests on the tabs 161 , then the wall stud 142 will be centered . these tabs 161 are preferably constructed to allow for self - centering of the studs 142 in a vertical direction during installation and when assembled . self - centering means the studs 142 are spaced above the middle wall 156 of the floor c - runner 150 b . fig1 is a side - view cross - section of the c - runner 150 b of fig1 along view xvii - xvii of fig1 including the tabs 161 as lifting elements for drainage and to assist in placement of the triangular wall studs . this shows a ramping edge 163 of the lifting element 161 can define an angle “ a ” of between 25 ° and 75 °, preferably about 64 ° with respect to a y - axis parallel to the second upstanding section 154 . the lifting element 161 can have a curved profile as shown in fig1 or form a substantially transverse , shelf ( not shown ). the lifting element 161 can have a height from horizontal middle wall 156 to the highest point of its open mouth 165 of about 0 . 5 to 1 inch and a width at its open mouth 165 along horizontal middle wall 156 of about 0 . 5 to 1 inch . fig1 is a perspective - view of the c - runner 150 b of fig1 including the tabs 161 as lifting elements for drainage and to assist in placement . fig1 shows a top view of another alternative embodiment of the triangular stud 162 without the notches , but having a symmetrically overlapping corner forming a seam or punch connection 164 . fig2 shows a top view of another alternative embodiment of the triangular stud 172 without the notches , but having a side including a symmetrically overlapping section forming a seam or punch connection 174 . fig2 shows a top view of the embodiment of fig1 further including blocking 180 applied to the face of the studs to add structural stability . if the wall boards 14 , 15 are horizontal then one screw 35 may be sufficient as shown in the center stud 142 , but when the panels are vertical two screws are employed as shown in the left and right triangular studs 142 . fig2 shows a perspective view of the blocking 180 of fig2 . the blocking 180 has a center wall 186 and upright walls 184 defining a series of gaps 188 for engaging respective triangular studs 142 . fig2 is a perspective view of an embodiment 191 of a shaft wall assembly of the invention employing floor c - runner 150 a , ceiling c - runner triangular studs 142 , and the blocking 180 of fig2 . the studs 12 can take the form of any stud having a triangular cross section suitable for placing in the present c - runner or j - runner . typical materials for the studs include steel . for beginning or terminating a wall , typically a metal framing member with a c or l profile is used . the c - runners , j - runners , and the triangular studs of the invention can be formed of any suitable material . typical materials include steel , for example 24 gauge ( 0 . 024 in , 0 . 6 cm ) or 20 gauge ( 0 . 035 in , 0 . 9 cm ) or other suitable gauges . the c - runners and j - runners and triangular studs can be formed by stamping or roll forming . to form the lifting elements , e . g . lifting element 151 or protrusions 158 of a runner , the runner can be lanced , stamped , pierced or notched . c - runners and j - runners employed in the present invention including a bottom ( middle ) section 71 , a shorter wall 69 , and lifting elements 129 . with reference to fig1 , c - runner 150 a typically has a total width “ a ” of from about 2 to 6 inches ( 5 . 1 to 15 . 2 cm ), typically either 2 . 5 or 4 . 0 inches ( 6 . 4 or 10 . 2 cm ), between its first upstanding wall 152 and its second upstanding wall 154 . the first and second upstanding walls typically have a height “ b ” of from about 0 . 75 to 2 . 0 inches ( 1 . 9 to 5 . 1 cm ), preferably approximately 1 inch ( 2 . 54 cm ). j - runners are the same except the shorter upstanding wall typically has a height of from about 0 . 75 to 2 . 0 inches ( 1 . 9 to 5 . 1 cm ), preferably approximately 1 inch ( 2 . 54 cm ), while the taller upstanding wall typically has a height of from about 1 . 5 to 4 inches ( 3 . 8 to 10 . 2 cm ), preferably about 2 . 0 to 2 . 5 inches ( 5 . 1 to 6 . 4 cm ), more preferably about 2 . 1 inches ( 5 . 3 cm ). although fig2 shows an installation with a floor c - runner 110 of the invention , i . e ., with lifting elements 159 , and the ceiling c - runner 11 without any lifting elements , it is considered within the scope of the invention to utilize two same c - runners of the invention , e . g ., two c - runners 110 , i . e ., one above the triangular studs 142 and one below the triangular studs 142 . likewise , it is considered within the scope of the invention to utilize a first j - runner of one embodiment of the invention in combination with a c - runner of another embodiment of the invention . likewise it is within the scope of the invention to substitute the different embodiments of triangular studs for each other . likewise , a similarly modified j - runner may be employed for both the floor runner and ceiling runner . the invention has many advantages . it employs one or more , preferably two or more , most preferably 2 or 3 , layers of wall board attached to one side of the triangular studs . the studs are triangular so the pointed end of the screw goes into the stud and is not exposed . thus , the shaft wall of the invention does not need an inner liner panel wall as do shaft walls made with c - h studs . all the wall boards of the present shaft wall assembly are actually attached to studs rather than having some attached and others slidingly held by a runner and c - h studs . generally in assembling the shaft wall assembly the triangular studs are not attached to the top or bottom j - runner . thus , to assist in placing the triangular stud , preferably the triangular stud has the notch described above for mating with an indentation on the inner shorter wall of the j - runner . another preferred enhancement to assist in placing the triangular stud is for the j - runner to have the above - described protrusions along its outer taller wall to form cavities in which to locate an edge of the triangular stud . triangular studs are stronger than c - h studs for a given composition and gage of metal from which they are made . thus , the shaft wall assemblies of the present invention can be made taller than shaft wall assemblies made with c - h studs . a computer assisted design ( cad ) simulation was run to compare a conventional 20 gauge c - stud with a 25 gauge triangle studs of the present invention . the 25 gauge triangle studs of the present invention was notched as shown by fig7 and had the cross - section configuration shown in fig1 . the cad simulation showed the triangular stud configuration has multiple advantages . it has greater moment of inertia about strong “ x ” access allowing for increase in limiting heights . it also has much greater weak moment of inertia about “ y ” access allowing for greater unbraced lengths , especially in instances where wallboard sheathing is only on one side . the stud allows easy of installation in case of a vertical board joint since there is more space for two rows of fasteners . it should be apparent that embodiments other than those specifically described above may come within the spirit and scope of the present invention . hence , the present invention is not limited by the above description .