Kenya Engineer joined the Institution of Engineers of Kenya (IEK) Mombasa branch on Wednesday 9th December 2015 as they visited the ongoing works on the Standard Gauge Railway (SGR) Project. Eng. Steven Ngige, the chairperson of IEK Mombasa branch functions committee, who organised the


Kenya Engineer joined the Institution of Engineers of Kenya (IEK) Mombasa branch on Wednesday 9th December 2015 as they visited the ongoing works on the Standard Gauge Railway (SGR) Project. Eng. Steven Ngige, the chairperson of IEK Mombasa branch functions committee, who organised the

visit recognised the importance of the project to engineers and Kenyans in general. The visit was organised to expose engineers to the progress of the project and give them a chance to get their questions answered about the project. Facilitating the visit was Eng. James Karanja representing TSDI-APEC-EDON Consortium. He let the IEK members through the different aspects of the project in details. 

The Mombasa Nairobi railway is located in Kenya, and lies in a southeast to northwest direction passing through Mombasa, Kilifi, Kwale, Taita Taveta, Makueni, Kajiado, Machakos and Nairobi Counties. The project will connect Mombasa, Kenya’s port city, and Nairobi, the capital city of Kenya, with overall length of the principal line of 472.253 km.


Parameter                      Details

Gauge                     1435mm

Number of main lines     Single line

Design driving speed of passenger trainPassenger car 120 km/hr bus; freight car 80 km/hr

The minimum radius of curveNormal 1200 m, difficult 800 m, limited speed section is determined combining with design speed

Ruling grade            Double locomotive 12%

Axle weight                     25t

Traction type            Internal combustion, electrification condition reserved

The type of locomotivePassenger car; DF4D (passenger); Freight car; DF8B

Traction load          4000t, 5000t condition reserved

Construction clearanceDouble stack container transportation fundamental construction clearance


Main works

The length of the subgrade of the whole line is 442.629 km, accounting for 93.7% of the total length of the line. Sventy six sets of girder type extra-large, large and middle size bridges are set, calculated as 29,687.17 linear meters, and the bridge length accounts for 6.3% of the total length of the line. There will be 22 sets of frame bridges, calculated as 630 linear meters (7180m2); culvert 27,746 horizontal linear meters. 33 stations are set for the whole line in which 2 are origin and terminal stations, 5 are intermediate stopping stations, and 26 are crossing stations.

The points of interest during the IEK Mombasa branch visit included Mombasa Port station and marshalling yard to see the land reclamation measures and the marshalling yard construction. Another point of interest was the Mazeras super major bridge that consists of a continuous beam construction due to the long span to cross the Dongo Kundu bypass.

Other areas that the group visited included the Mombasa super major bridge for the environmental protection of the Mangrove forests, Mugalani station, Bachuma camp, Voi super major bridge, Kyulu super bridge crossing, Kyulu railways station, bridge girders erection at section 3, track laying exercise at section 6, and the beam sleeper precasting and track assembly at section 6. The works are progressing as captured below.

Section 1

This section covers a total length of 70 km from DK 0+000 to DK 70+000. The section also includes land reclamation from the Indian Ocean. It consists of 5 Subsections, 3 (Miritini DK0-DK21, Mariakani DK21-DK37, Taru DK37-DK70). Subsections are fully equipped with independent batching plant and testing laboratories with the main laboratory located at Mariakani Sub-section. The Sub-sections also accommodate the contractors and the consultant staff.

The section consists of 64.8 km of subgrade works, 5,208.88 m of main track bridges, 10 in number, 124 culverts (drainage and loading), 3- underpass/ frame bridge (DK 27+957 DK50+600 DK51+917), 21 overpasses and 6 stations. The total subgrade works that had been done in this section was 49.11%, cumulative works done on the bridges being 54.59, while that done on the culverts being 66.65%.

The section also comprises 21 overpasses/ road bridges with 2 under construction ( DK 31+484 and DK 38+802). The overpasses will adopt the use of simply supported post-tensioned prestressed concrete slabs, which are also under construction

Eng. Karanja observed that some of the challenges in this section include the reclamation works on the Mombasa port station and marshalling yard. The lack of sand and issues around land acquisition, which delay the project. 

Section 2

This section covers a total length of 144 km from DK 70+000 to DK 214+000. The section consists of 137.28 km of subgrade works. 22 main track bridges, 2 road bridges, 2 frame bridges, 6 reinforced concrete frame culverts, 148 reinforced concrete slab culverts and 9 stations some being minor for trains crossing. The section has 4 sub sections each fully equipped with its independent batching plant and testing laboratories with the main laboratory being located at Voi sub section. The sub sections also accommodate the contractors’ team and consultants’ staff.

121.71 km of subgrade work is already done representing 94% of the total scope of earth works. There are 22 main track bridges under construction each at different stages of construction with all the bridges at substructure stages. The piles already sunk and concreted includes 621 out of the total 641 in number at varying lengths as per the original/ revised design accounting to 96.8% of the total piles. There are 106 open cut foundations with 90 already completed accounting to 84.9% of the total number of foundations. The pile caps already completed are 92 out of the total 134 accounting for 68.7%. Bridge piers, portal piers, and abutments completed are 171 out of the total 240 thus accounting to 71.3% completed. The reinforced concrete frame culverts and reinforced concrete slab culverts together with frame bridges completed add to 99%.

Section 3

This section covers a distance of 40 Km form DK 214 to DK 254. The section has 38 box culverts of which 24 are mainly for drainage, 6 are for combined use for traffic and drainage while 8 are mainly for traffic. 17 bridge spans have been erected in section 3.

Section 6 and 7

Beam production, sleeper manufacture, ballast production, and track laying.

There are two factories involved in beam production, sleeper manufacture, track panel assembly, and track laying.

a.Section 6 located at DK 246 is in charge of the above from DK 247+000 to DK 000+000

b.Section 7 located at DK 350 in charged with the above from DK 247+ 000 to DK 472+000

SGR sleepers

The SGR sleepers are pre-stressed. They are made of reinforced concrete with concrete of class 60 and 6.25 mm diameter round steel bars.

They have 3 types of sleepers

•Type I pre-stressed reinforced concrete point sleeper is adopted for turnouts

•Type II pre-stressed sleeper is adopted for main line and station line

•Type III pre-stressed reinforced concrete bridge sleeper is adopted for bridges

Sleeper Manufacture

SectionTarget Output Current Output

Section 6     545,174269,140

Section 7     490,000258,515


Beam Production and erection

There are three types of beams that are produced namely 32, 24, and 16 meter span beams. The beam is made of reinforced concrete using concrete of class 55 with reinforcement of 8 mm and 12mm diameter twisted bars. The beam is post- tensioned using steel strands. 

Beam production

SectionTarget outputCurrent output

Section 6    722               380

Section 7   842               428


Ballast production is 800,000 m3 and production to date slightly above 50%.

The visit by Engineers discovered that the project had gained a lot of ground with most of the civil works tackled. The contractor and consultants are progressing well with the works and soon Kenyans will be surprised at the magnitude of the transformation resulting from the SGR project. 


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