Klenk & Sohn

What Klenk & Sohn does

Klenk & Sohn GmbH is a German private infrastructure construction company headquartered in Modautal-Ernsthofen with a branch office in Offenbach. Founded in 1920 and incorporated as a GmbH in 1980 (consolidated in its current form in 2017), the company delivers turnkey ("schlüsselfertig") infrastructure projects for telecommunications and energy networks. Its core offering bundles seven integrated service lines: project management, route and permit planning, civil engineering (Tiefbau), horizontal directional drilling (Bohrtechnik, including HDD Spülbohrverfahren since 1998 and cable ploughing since 1991), cable technology (Kabeltechnik) including fiber optic and micro-duct installation, precision documentation using GPS/tachymeter, and 24/7 maintenance. The company is positioned as a "Komplett-Anbieter" (full-service provider) for FTTX (FTTB/FTTC/FTTH) broadband and energy cable networks, with technical certifications including ISO 9001:2008, RAL-Gütezeichen 905 (Fernmeldebau modules 1–4), and RAL-GZ 962/2 (Kabelleitungstiefbau).

The company generates project-based professional services revenue through direct enterprise sales and public procurement/tendering. Its three primary customer segments are: (1) telecommunications operators, with named customers including Deutsche Telekom Technik GmbH and NetCologne delivering FTTB, FTTC, and FTTH projects; (2) energy utilities, including GGEW AG; and (3) municipalities and public-sector entities, where the company has delivered multi-year intercommunal broadband programs including IKbit (Kreis Bergstraße, 10 municipalities), Breitband Odenwald (15 municipalities, recognized as a model project for Hesse), Breitband Main-Kinzig, and Darmstadt-Dieburg FTTC covering 19 municipalities and 290,000 residents. The company also delivers school fiber connectivity programs (34 schools in Odenwaldkreis, 72 schools in Kreis Offenbach). Geographic operations span multiple German states including Hessen, Baden-Württemberg, Bavaria, North Rhine-Westphalia, and Rhineland-Palatinate. Ownership is family-held across multiple generations with Udo Klenk as sole Managing Director since 1992 alongside Sebastian Jacobs and Paul Quiskamp; there are no disclosed external institutional investors. Headcount is 51–100 employees.

Name

Klenk & Sohn

Legal name

Klenk & Sohn GmbH

Website

https://www.klenkfirm.de

Company type

Private

Operating status

Operating

Headcount range

51–100 employees

Short description

Klenk & Sohn GmbH is a German family-owned infrastructure construction firm delivering turnkey FTTX broadband, civil engineering, drilling, and cable-installation services to telecom operators, energy utilities, and municipal/public-sector clients across multiple German states.

Ownership category

akta.pro rank

Product category

Telecommunications Infrastructure Construction

NAICS

Power and Communication Line and Related Structures Construction (237130)

SIC

Water, Sewer, Pipeline, Comm & Power Line Construction (1623), Communications Services, Nec (4899)

akta.pro primary industry

Network Engineering, Integration & Field Deployment Services (Design, Build, Test) (EUADAIAM)

akta.pro secondary industries

Fiber Splicing, Testing & Commissioning (OTDR, Acceptance, Turn-Up) (IMAFAIAB), Turnkey distribution buildouts (feeders, reclosers, capacitor banks, line extensions) (EUADAKAK)

Keywords

• Fiber optic construction
• Broadband network infrastructure
• Telecommunications civil engineering
• Horizontal directional drilling
• Network documentation services

Headquarters

HQ city

Darmstadt

HQ country

Germany

HQ region

Europe

Offices2 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Infrastructure, Technology or R&D, Marketing or Sales, Supply Chain

Revenue model

1. Infrastructure Construction Services: Klenk & Sohn generates revenue through project-based infrastructure construction contracts for telecommunications and energy networks. Services include project management, planning, civil engineering, drilling, cable installation, and documentation — delivered as a turnkey (schlüsselfertig) package from a single provider. Revenue is derived from large-scale public and private sector infrastructure projects including FTTX broadband deployment, awarded via tendering or direct contracting.

Go-to-market motion1 record

Distribution channels2 records

Marketing channels5 records

Core offering

Klenk & Sohn is a full-service (Komplett-Anbieter) infrastructure construction provider for telecommunications and energy networks in Germany. The company delivers turnkey FTTX (fiber-to-the-x) broadband projects, bundling project management, route planning, civil engineering, horizontal directional drilling (HDD), cable installation, microduct technology, GPS/tachymeter documentation, and 24/7 maintenance under one provider. Services are delivered as a single 'schlüsselfertig' (turnkey) package to telecom operators, energy utilities, and municipalities.

Product overview

Klenk & Sohn is a full-service provider for infrastructure supply facility construction in telecommunications and energy. The company operates as a single unified service organization offering project management, planning, civil engineering (Tiefbau), drilling technology (Bohrtechnik), cable technology (Kabeltechnik), documentation, and maintenance services as a turnkey package. All relevant project interfaces and required expertise are bundled under one roof. The subsidiary PEB Breitband GmbH & Co.KG handles intercommunal broadband projects. Services span from route planning through execution to documentation, enabling cost-effective gigabit and broadband network construction.

Differentiator

Problem solved

Functional benefit

Brands

• IKbit: Interkommunales Breitbandnetz - joint venture project for broadband network in Kreis Bergstraße (Weschnitztal-Überwald region)

Products and services

• Project Management (Projektmanagement) Comprehensive project management services for telecommunications and energy infrastructure projects, including market analysis, risk assessment, concept development, investment and financing calculations, and coordination of all project-relevant processes.
• Planning (Planung) Planning services covering route planning (Trassenplanung), permit acquisition (Genehmigungen), construction planning, GPS/tachymeter surveying (Einmessung), and documentation as a complete turnkey package. Includes network concepts, feasibility studies, approval and execution planning, and environmental compensation planning.
• Civil Engineering (Tiefbau) Conventional and special civil engineering services for telecommunications and energy line construction, including cable construction, cable duct installation, and surface design. Covers opening and restoration of paved surfaces, underground cable laying, and shaft construction.
• Drilling Technology (Bohrtechnik) Horizontal directional drilling services using the mud drilling method (Spülbohrverfahren) as an economical and environmentally friendly alternative for laying cables and pipelines. Capable of passing under nature reserves, biotopes, buildings, rivers, highways, and railways without surface disruption.
• Cable Technology (Kabeltechnik) Complete spectrum of cable mounting, cable laying, microtechnology, and in-house networking including fiber optic and copper cable installation, splicing, and active component installation. Includes microduct and microcable blowing for efficient fiber deployment.
• Documentation (Dokumentation) On-site surveying of constructed facilities using GPS or tachymeter, collection of trade-specific documentation materials (bore protocols, cable laying protocols, calibration protocols, compaction records), creation of inventory plans and complete project documentation per customer specifications.
• Maintenance (Maintenance) Year-round, 24/7/365 emergency standby (Rufbereitschaft) for civil engineering, cable pulling, fault measurement, and assembly; preventive maintenance including annual shaft inspections, route inspections, and cable measurements; plan information services including cable protection instructions and third-party site briefings.

Quantifiable outcome

• 125 km of new cable route and 265 km of fiber optic cable installed in Allgäu FTTB project (2017-2019)
• +4 more outcomes

Named customers9 records

Segments3 records

Ideal customer profiles3 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature6 records

Partnerships

Five partnerships are on record, tiered core and minor.

• HEAG MediaNet GmbHcoreStrategic or Co-development Partner · 1 January 2001Klenk & Sohn formed an ARGE (working group/joint venture) with HEAG MediaNet GmbH in 2001 for the joint execution of broadband infrastructure projects. HEAG MediaNet GmbH serves as the network operator for the broadband network in the Odenwaldkreis. The partnership combines Klenk & Sohn's construction expertise with HEAG MediaNet's network operation capabilities.
• PEB Breitband GmbH & Co.KGcoreStrategic or Co-development PartnerPEB Breitband GmbH & Co.KG is a subsidiary company jointly established by Klenk & Sohn GmbH and HSE Medianet. It was awarded the contract for the intercommunal broadband network (IKbit) in the Kreis Bergstraße (Weschnitztal-Überwald area) following a Europe-wide tender. PEB functions as the operating entity delivering the broadband network project.
• Gütegemeinschaft Leitungstiefbau e.V.minorOthersTrade association for cable civil engineering quality. Udo Klenk serves as a board member (Präsidiumsmitglied) and Andreas Kühl is a member of the quality committee. The association promotes uniform and verifiable quality standards in cable civil engineering and duct laying.
• FFB Fachverband Fernmeldebau e.V.minorOthersThe FFB Fachverband Fernmeldebau e.V. is the association of private companies in the telecommunications construction, cable installation, and communication technology sectors in Germany. Founded in 1967, it represents companies ranging from mid-sized craft businesses to internationally operating large enterprises.
• Gütegemeinschaft Fernmeldebau e.V.minorOthersQuality association for telecommunications construction. Udo Klenk is a founding member of the Gütegemeinschaft Fernmeldebau. The association certifies member companies for quality in cable installation, cable assembly, cable measurement technology, and FTTX planning and execution.

Scale indicators7 records

Recent moves9 records

Expansion highlights5 records

Market position

Competitive moat4 records

Key risks5 records

Key highlights7 records

Customer concentration

• Facebookfacebook.com/Firma.Klenk.Sohn

Compliance3 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles3 records

Subsidiaries4 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Klenk & Sohn